Polymer compositions and use of the same

ABSTRACT

Provided herein, inter alia, are polymeric compositions and systems useful for maintaining particle dispersions for extended periods of time. Also provided are dry polymeric compositions and systems that are able to undergo fast hydration. Methods for using such compositions and systems are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 62/818,847, filed onMar. 15, 2019, the entire disclosure of which is incorporated herein byreference.

BACKGROUND

There exist many fields where the maintenance in suspension of particlesis determining (particles of pigments in compositions of paint orvarnish type, for example). More specifically, in the field of oilextraction, numerous stages are carried out by injecting fluids underpressure within subterranean formations, where it is often of use tokeep particles in suspension in order to prevent them from sedimentingout in spite of the extreme temperature and pressure conditionsgenerally employed in the subterranean formation.

For the purpose of inhibiting the phenomenon of separation by settling,it is possible to add additives which make it possible to keep theparticles in suspension. A certain number of these additives have beendescribed, which include in particular crosslinked or non-crosslinkedpolymers, polysaccharides and their derivatives, such as xanthan gum,cellulose ethers or alternatively guars, and its derivatives crosslinkedwith borate or zirconate. Nevertheless, it emerges that these suspendingagents decompose when the temperature exceeds 150° C. This limitationthus renders these additives unusable for applications at a highertemperature (typically greater than 150° C., often between 150 and 200°C., indeed even ranging up to more than 200° C.). In addition, in thecase of the use of these agents in the vicinity of oil-bearing rocks,namely in particular in fluids such as drill-in fluid, completion fluid,fracturing fluid, acidizing fluid or spacer fluids, they exhibit thedisadvantage of decomposing in the form of insoluble residues whichcannot be properly removed.

Still, there remains a need for improved compositions and methods forsuspension of particles.

SUMMARY

The present disclosure provides polymeric compositions and systemsuseful for maintaining particle dispersions for extended periods oftime. Polymeric compositions and systems are also useful for maintainingparticle dispersions for extended periods of time at elevatedtemperatures and/or in high brine conditions. Also provided are drypolymeric compositions and systems that are able to undergo fasthydration.

In an aspect, the present disclosure provides a composition including:

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof;

iii) at least one glycol ether having a structure of

herein R¹ is hydrogen or acetate; R² is C₁-C₈ alkyl or phenyl; p and qare the same or different and p and q are independently an integer from1 to 6, wherein the composition has a hydration rate of about 70% orgreater.

In embodiments, p and q are independently 2 or 3. In embodiments, theglycol ether comprises one or more selected from diethylene glycolmethyl ether, diethylene glycol ethyl ether, diethylene glycol propylether, diethylene glycol n-butyl ether, diethylene glycol t-butyl ether,diethylene glycol pentyl ether, diethylene glycol hexyl ether,diethylene glycol heptyl ether, diethylene glycol octyl ether,diethylene glycol phenyl ether, diethylene glycol methyl ether acetate,diethylene glycol ethyl ether acetate, diethylene glycol propyl etheracetate, diethylene glycol n-butyl ether acetate, diethylene glycolt-butyl ether acetate, diethylene glycol pentyl ether acetate,diethylene glycol hexyl ether acetate, diethylene glycol heptyl etheracetate, diethylene glycol octyl ether acetate, diethylene glycol phenylether acetate, dipropylene glycol methyl ether, dipropylene glycol ethylether, dipropylene glycol propyl ether, dipropylene glycol n-butylether, dipropylene glycol t-butyl ether, dipropylene glycol pentylether, dipropylene glycol hexyl ether, dipropylene glycol heptyl ether,dipropylene glycol octyl ether, dipropylene glycol phenyl ether,dipropylene glycol methyl ether acetate, dipropylene glycol ethyl etheracetate, dipropylene glycol propyl ether acetate, dipropylene glycoln-butyl ether acetate, dipropylene glycol t-butyl ether acetate,dipropylene glycol pentyl ether acetate, dipropylene glycol hexyl etheracetate, dipropylene glycol heptyl ether acetate, dipropylene glycoloctyl ether acetate and dipropylene glycol phenyl ether acetate. Inembodiments, the glycol ether is diethylene glycol hexyl ether.

In some embodiments, the composition includes the glycol ether in anamount from about 3 wt % to about 15 wt % based on the total weight ofthe composition.

In embodiments, the composition further includes a salt containing alkylsulfate (—SO₄) anion. In embodiments, the salt includes sodium laurylsulfate.

In an aspect, a method of producing a polymer powder is provided. Themethod includes: combining a composition of claim 1 and water to form anaqueous polymer composition; synthesizing a polymer by polymerizing theaqueous polymer composition; drying the polymer; and forming the polymerpowder from the dried polymer.

In some aspects, the polymer powder is formed by grinding or milling. Inembodiments, the polymer powder has a particle size of from about 1 μmto about 1 mm.

In an aspect, a powder composition is provided. The powder compositionincludes a polymer including:

i) at least one hydrophobic monomer selected from the group consistingof n-hexyl (meth)acrylate, n-octyl (meth)acrylate, octyl(meth)acrylamide, lauryl (meth)acrylate, lauryl (meth)acrylamide,myristyl (meth)acrylate, myristyl (meth)acrylamide, pentadecyl(meth)acrylate, pentadecyl (meth)acrylamide, cetyl (meth)acrylate, cetyl(meth)acrylamide, oleyl (meth)acrylate, oleyl (meth)acrylamide, erucyl(meth)acrylate, erucyl (meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof;

iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.

In embodiments, the glycol ether is diethylene glycol hexyl ether. Inembodiments, the powder composition has a particle size of from about 1μm to about 1 mm.

In an aspect, the present disclosure provides a slurry, which includes apolymer; an aqueous component; and a proppant.

In embodiments, the polymer includes:

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; and

iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6;wherein the polymer in the slurry has a hydration rate of about 70% orgreater. For instance, the hydration may be reached within severalminutes (e.g., 1 to 10 minutes, or 3 minutes) by low shear mixing rateless than about 10,000 rpm, such as at about 1,000, about 1,250, about1,500, about 1,750, about 2,000 rpm, about 2,250, about 2,500 rpm, about3,000, about 3,500, about 4,000, about 5,000, about 6,000, about 7,000,about 8,000, about 9,000, or about 9,500. In embodiments, the aqueouscomponent is selected from distilled water, fresh water, sea water,brines, salt water, produced water, recycled water, industrial wastewater, waste water associated with oil production, and combinationsthereof. In embodiments, the glycol ether is diethylene glycol hexylether.

In an aspect, the present disclosure provides a method of fracturing asubterranean formation. The method includes injecting a fracturing fluidincluding a slurry as described herein into at least a portion of thesubterranean formation at pressures sufficient to fracture theformation. In embodiments, the slurry includes diethylene glycol hexylether.

In another aspect, provided is a method of suspending a proppant of afracturing fluid. The method includes mixing an aqueous fluid and theproppant. In embodiments, the aqueous fluid includes a polymer includingthe composition as described herein and water. In embodiments, thepolymer includes diethylene glycol hexyl ether.

Other aspects of the invention are disclosed infra.

DETAILED DESCRIPTION

The inventors have discovered polymeric systems for particle dispersionswhich, surprisingly, can be used in lower amounts in comparison withconventional carrier systems while providing enhanced particledispersion capabilities. In certain embodiments, an aqueous compositionthat includes water and a polymer of the present disclosure exhibits aparticle suspension time of at least 1 hour. In other embodiments, theparticle suspension time lasts at least 2 hours. In yet anotherembodiment, the particle suspension time lasts at least 4 hours. In someembodiments, the particle suspension time lasts over a period of 24hours. In other embodiments, the aqueous composition suspends particlesat a temperature of about 68° F. to about 350° F. (or any temperaturewithin this range).

Polymer Composition

In one aspect, provided is a polymer composition (“composition”), whichmay be used for producing the above polymer. In certain embodiments, thecomposition includes at least one hydrophobic monomer, at least onehydrophilic monomer, and at least glycol ether component.

In embodiments, the hydrophobic monomer can include one or more selectedfrom n-hexyl (meth)acrylate, n-octyl (meth)acrylate, octyl(meth)acrylamide, lauryl (meth)acrylate, lauryl (meth)acrylamide,myristyl (meth)acrylate, myristyl (meth)acrylamide, pentadecyl(meth)acrylate, pentadecyl (meth)acrylamide, cetyl (meth)acrylate, cetyl(meth)acrylamide, oleyl (meth)acrylate, oleyl (meth)acrylamide, erucyl(meth)acrylate, erucyl (meth)acrylamide, and combinations thereof.

In some embodiments, the hydrophilic monomer includes one or moreselected from acrylate, acrylate salts, acrylamide,2-acrylamido-2-methylpropane sulfonic acid, and2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof. In some embodiments, the glycol ether component includes one ormore compounds having a structure of

wherein R¹ is hydrogen or acetate; R² is C₁-C₈ alkyl or phenyl; p and qare the same or different and p and q are independently an integer from1 to 6.

In embodiments, R² is C₁-C₈ alkyl. In embodiments, R² is substituted orunsubstituted methyl, ethyl, propyl, n-butyl, t-butyl, pentyl, hexyl,heptyl, or octyl. In embodiments, R² is unsubstituted methyl, ethyl,propyl, n-butyl, t-butyl, pentyl, hexyl, heptyl, or octyl. Inembodiments, R² is methyl. In embodiments, R² is ethyl. In embodiments,R² is propyl. In embodiments, R² is n-butyl. In embodiments, R² ist-butyl. In embodiments, R² is pentyl. In embodiments, R² is hexyl. Inembodiments, R² is heptyl. In embodiments, R² is octyl. In embodiment R²is substituted or unsubstituted phenyl. In embodiments, R² isunsubstituted phenyl.

In embodiments, p and q are independently 2 or 3. In embodiments, p is 2or 3. In embodiments, q is 2 or 3. In embodiments, p is 2. Inembodiments, q is 2. In embodiments, p is 3. In embodiments, q is 3.

In embodiments, the glycol ether component is selected from diethyleneglycol methyl ether, diethylene glycol ethyl ether, diethylene glycolpropyl ether, diethylene glycol n-butyl ether, diethylene glycol t-butylether, diethylene glycol pentyl ether, diethylene glycol hexyl ether,diethylene glycol heptyl ether, diethylene glycol octyl ether,diethylene glycol phenyl ether, diethylene glycol methyl ether acetate,diethylene glycol ethyl ether acetate, diethylene glycol propyl etheracetate, diethylene glycol n-butyl ether acetate, diethylene glycolt-butyl ether acetate, diethylene glycol pentyl ether acetate,diethylene glycol hexyl ether acetate, diethylene glycol heptyl etheracetate, diethylene glycol octyl ether acetate, diethylene glycol phenylether acetate, dipropylene glycol methyl ether, dipropylene glycol ethylether, dipropylene glycol propyl ether, dipropylene glycol n-butylether, dipropylene glycol t-butyl ether, dipropylene glycol pentylether, dipropylene glycol hexyl ether, dipropylene glycol heptyl ether,dipropylene glycol octyl ether, dipropylene glycol phenyl ether,dipropylene glycol methyl ether acetate, dipropylene glycol ethyl etheracetate, dipropylene glycol propyl ether acetate, dipropylene glycoln-butyl ether acetate, dipropylene glycol t-butyl ether acetate,dipropylene glycol pentyl ether acetate, dipropylene glycol hexyl etheracetate, dipropylene glycol heptyl ether acetate, dipropylene glycoloctyl ether acetate, dipropylene glycol phenyl ether acetate, andcombinations thereof. In embodiments, the glycol ether component isdiethylene glycol hexyl ether (DGHE).

In embodiments, the composition includes one or more glycol ethercomponents selected from diethylene glycol methyl ether, diethyleneglycol ethyl ether, diethylene glycol propyl ether, diethylene glycoln-butyl ether, diethylene glycol t-butyl ether, diethylene glycol pentylether, diethylene glycol hexyl ether, diethylene glycol heptyl ether,diethylene glycol octyl ether, diethylene glycol phenyl ether,diethylene glycol methyl ether acetate, diethylene glycol ethyl etheracetate, diethylene glycol propyl ether acetate, diethylene glycoln-butyl ether acetate, diethylene glycol t-butyl ether acetate,diethylene glycol pentyl ether acetate, diethylene glycol hexyl etheracetate, diethylene glycol heptyl ether acetate, diethylene glycol octylether acetate, diethylene glycol phenyl ether acetate, dipropyleneglycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycolpropyl ether, dipropylene glycol n-butyl ether, dipropylene glycolt-butyl ether, dipropylene glycol pentyl ether, dipropylene glycol hexylether, dipropylene glycol heptyl ether, dipropylene glycol octyl ether,dipropylene glycol phenyl ether, dipropylene glycol methyl etheracetate, dipropylene glycol ethyl ether acetate, dipropylene glycolpropyl ether acetate, dipropylene glycol n-butyl ether acetate,dipropylene glycol t-butyl ether acetate, dipropylene glycol pentylether acetate, dipropylene glycol hexyl ether acetate, dipropyleneglycol heptyl ether acetate, dipropylene glycol octyl ether acetate anddipropylene glycol phenyl ether acetate. In embodiments, the compositionincludes diethylene glycol hexyl ether. In embodiments, the compositionincludes diethylene glycol hexyl ether and one or more of diethyleneglycol methyl ether, diethylene glycol ethyl ether, diethylene glycolpropyl ether, diethylene glycol n-butyl ether, diethylene glycol t-butylether, diethylene glycol pentyl ether, diethylene glycol heptyl ether,diethylene glycol octyl ether, diethylene glycol phenyl ether,diethylene glycol methyl ether acetate, diethylene glycol ethyl etheracetate, diethylene glycol propyl ether acetate, diethylene glycoln-butyl ether acetate, diethylene glycol t-butyl ether acetate,diethylene glycol pentyl ether acetate, diethylene glycol hexyl etheracetate, diethylene glycol heptyl ether acetate, diethylene glycol octylether acetate, diethylene glycol phenyl ether acetate, dipropyleneglycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycolpropyl ether, dipropylene glycol n-butyl ether, dipropylene glycolt-butyl ether, dipropylene glycol pentyl ether, dipropylene glycol hexylether, dipropylene glycol heptyl ether, dipropylene glycol octyl ether,dipropylene glycol phenyl ether, dipropylene glycol methyl etheracetate, dipropylene glycol ethyl ether acetate, dipropylene glycolpropyl ether acetate, dipropylene glycol n-butyl ether acetate,dipropylene glycol t-butyl ether acetate, dipropylene glycol pentylether acetate, dipropylene glycol hexyl ether acetate, dipropyleneglycol heptyl ether acetate, dipropylene glycol octyl ether acetate anddipropylene glycol phenyl ether acetate.

In embodiments, the composition includes the glycol ether component inan amount from about 1 wt % to about 30 wt % based on the total weightof the composition. In embodiments, the composition includes the glycolether component in an amount from about 1 wt % to about 25 wt % based onthe total weight of the composition. In embodiments, the compositionincludes the glycol ether component in an amount from about 1 wt % toabout 20 wt % based on the total weight of the composition. Inembodiments, the composition includes the glycol ether component in anamount from about 1 wt % to about 15 wt % based on the total weight ofthe composition. In embodiments, the composition includes the glycolether component in an amount from about 2 wt % to about 15 wt % based onthe total weight of the composition. In embodiments, the compositionincludes the glycol ether component in an amount from about 3 wt % toabout 15 wt % based on the total weight of the composition. Inembodiments, the composition includes the glycol ether component in anamount from about 5 wt % to about 15 wt % based on the total weight ofthe composition.

In embodiments, the composition further includes a salt containing alkylsulfate. In embodiments, the alkyl sulfate salt may be represented asR³OSO₃M, where R³ represents a C₁-C₂₄, C₁₀-C₂₄, or C₁₂-C₂₀ alkyl orhydroxyalkyl radical and M represents a cation selected from a metalcation, for example, alkali metal cation or alkali-earth metal cation,or the ammonium cation (NH₄ ⁺). In embodiments, the salt includes acation, such as ammonium ion (NH₄ ⁺), sodium ion (Na+), or calcium ion(Ca²⁺). In embodiments, the salt includes lauryl sulfate. Inembodiments, the salt includes sodium lauryl sulfate (SDS).

In embodiments, the composition may be used as a premix forpolymerization. For example, the premix includes monomer components(e.g., hydrophobic monomers and hydrophilic monomers) that ispolymerized into the polymer. In embodiments, the polymer includes oneor more polymers polymerized from the monomer components. Inembodiments, the polymer includes one or more polymers polymerized fromthe monomer components and the glycol ether component.

In embodiments, the polymer has a hydration rate of about 10% orgreater, about 15% or greater, about 20% or greater, about 25% orgreater, about 30% or greater, about 35% or greater, about 40% orgreater, about 45% or greater, about 50% or greater, about 55% orgreater, about 60% or greater, about 65% or greater, about 70% orgreater, about 75% or greater, about 80% or greater, about 85% orgreater, about 90% or greater, about 95% or greater, or about 99% orgreater.

Hydration rate of polymer can be defined as the ratio of the viscositiesmeasured at time x divided by the full hydration or equilibriumviscosity of the polymer solution. For example, the polymer has ahydration rate of 50% in 3 minutes if the polymer solution viscosityreaches 50% of the full hydration viscosity at the 3 minute mark.

When the polymer hydrates in water, the polymer chains may be releasedinto the water (e.g., fresh water or low TDS salt water) which buildsviscosity. The viscosity of the polymer solution increases withincreasing degree of hydration. For incomplete or low degree ofhydration, one can also see incomplete hydrated particles or fish eyesin the system. In embodiments, hydration rate of the composition when itis polymerized in the polymer may be increased at low shear mixing (forexample, less than 10,000 rpm). In embodiments, the polymer as beingadded with water or water component has a viscosity measured at 511 S⁻¹of greater than about 10 cp, of greater than about 15 cp, of greaterthan about 20 cp, of greater than about 25 cp, of greater than about 30cp, of greater than about 35 cp, of greater than about 40 cp, of greaterthan about 45 cp, of greater than about 50 cp, of greater than about 55cp, of greater than about 60 cp, of greater than about 65 cp, of greaterthan about 70 cp, of greater than about 75 cp, or of greater than about80 cp. In embodiments, when the 0.3 wt % of the polymer is added towater or water component, a viscosity thereof measured at 511 S¹ may beof greater than about 10 cp, of greater than about 15 cp, of greaterthan about 20 cp, of greater than about 25 cp, of greater than about 30cp, of greater than about 35 cp, of greater than about 40 cp, of greaterthan about 45 cp, of greater than about 50 cp, or of greater than about55 cp. In other embodiments, when the 0.6 wt % of the polymer is addedto water or water component, a viscosity thereof measured at 511 S⁻¹ maybe of greater than about 10 cp, of greater than about 15 cp, of greaterthan about 20 cp, of greater than about 25 cp, of greater than about 30cp, of greater than about 35 cp, of greater than about 40 cp, of greaterthan about 45 cp, of greater than about 50 cp, of greater than about 55cp, of greater than about 60 cp, of greater than about 65 cp, of greaterthan about 70 cp, of greater than about 75 cp, or of greater than about80 cp. In embodiments, the viscosities may be dependent on the polymerdosage and shear rate. For example, the viscosity can be as much as 80cp at a higher dosage of 0.6 wt % at 511 S⁻¹. In embodiments, anequivalent unit of viscosity, i.e. mPa/s (1 cp=1 mPa/s), may be usedwithout limitation.

In embodiments, the polymer includes hydrophilic monomers in an amountfrom about 50 wt % to about 99.9 wt % of the polymer. In embodiments,the polymer includes hydrophilic monomers in an amount from about 80 wt% to about 99.9 wt % of the composition. In embodiments, the polymerincludes hydrophobic monomers in a total amount from about 0.01 wt % toabout 50 wt % of the composition. In embodiments, the polymer includeshydrophobic monomers in a total amount from about 0.01 wt % to about 20wt % of the composition.

In embodiments, the polymer may be hydrated within 2 hours, within 1hour, within 55 minutes, within 50 minutes, within 45 minutes, within 40minutes, within 35 minutes, within 30 minutes, within 25 minutes, within20 minutes, within 15 minutes, within 10 minutes, within 9 minutes,within 8 minutes, within 7 minutes, within 6 minutes, within 5 minutes,within 4 minutes, within 3 minutes, within 2 minutes, or within 1minute, after adding the water (e.g., fresh water or low TDS saltwater).

In embodiments, a terminal end position of the polymer includes athiocarbonylthio functional group.

In a further aspect, a powder composition including the polymer isprovided. In embodiments, the polymer includes: i) at least onehydrophobic monomer selected from n-hexyl (meth)acrylate, n-octyl(meth)acrylate, octyl (meth)acrylamide, lauryl (meth)acrylate, lauryl(meth)acrylamide, myristyl (meth)acrylate, myristyl (meth)acrylamide,pentadecyl (meth)acrylate, pentadecyl (meth)acrylamide, cetyl(meth)acrylate, cetyl (meth)acrylamide, oleyl (meth)acrylate, oleyl(meth)acrylamide, erucyl (meth)acrylate, erucyl (meth)acrylamide, andcombinations thereof; ii) at least one hydrophilic monomer selected fromacrylate, acrylate salts, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid salts, andcombinations thereof; and iii) at least one glycol ether having astructure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.

In embodiments, R² is C₁-C₈ alkyl. In embodiments, R² is substituted orunsubstituted methyl, ethyl, propyl, n-butyl, t-butyl, pentyl, hexyl,heptyl, or octyl. In embodiments, R² is unsubstituted methyl, ethyl,propyl, n-butyl, t-butyl, pentyl, hexyl, heptyl, or octyl. Inembodiments, R² is methyl. In embodiments, R² is ethyl. In embodiments,R² is propyl. In embodiments, R² is n-butyl. In embodiments, R² ist-butyl. In embodiments, R² is pentyl. In embodiments, R² is hexyl. Inembodiments, R² is heptyl. In embodiments, R² is octyl. In embodiment R²is substituted or unsubstituted phenyl. In embodiment R² isunsubstituted phenyl. In embodiments, p and q are independently 2 or 3.In embodiments, p is 2 or 3. In embodiments, q is 2 or 3. Inembodiments, p is 2. In embodiments, q is 2. In embodiments, p is 3. Inembodiments, q is 3.

In embodiments, the glycol ether component is selected from diethyleneglycol methyl ether, diethylene glycol ethyl ether, diethylene glycolpropyl ether, diethylene glycol n-butyl ether, diethylene glycol t-butylether, diethylene glycol pentyl ether, diethylene glycol hexyl ether,diethylene glycol heptyl ether, diethylene glycol octyl ether,diethylene glycol phenyl ether, diethylene glycol methyl ether acetate,diethylene glycol ethyl ether acetate, diethylene glycol propyl etheracetate, diethylene glycol n-butyl ether acetate, diethylene glycolt-butyl ether acetate, diethylene glycol pentyl ether acetate,diethylene glycol hexyl ether acetate, diethylene glycol heptyl etheracetate, diethylene glycol octyl ether acetate, diethylene glycol phenylether acetate, dipropylene glycol methyl ether, dipropylene glycol ethylether, dipropylene glycol propyl ether, dipropylene glycol n-butylether, dipropylene glycol t-butyl ether, dipropylene glycol pentylether, dipropylene glycol hexyl ether, dipropylene glycol heptyl ether,dipropylene glycol octyl ether, dipropylene glycol phenyl ether,dipropylene glycol methyl ether acetate, dipropylene glycol ethyl etheracetate, dipropylene glycol propyl ether acetate, dipropylene glycoln-butyl ether acetate, dipropylene glycol t-butyl ether acetate,dipropylene glycol pentyl ether acetate, dipropylene glycol hexyl etheracetate, dipropylene glycol heptyl ether acetate, dipropylene glycoloctyl ether acetate, dipropylene glycol phenyl ether acetate, andcombinations thereof. In embodiments, the glycol ether component isdiethylene glycol hexyl ether (DGHE).

In embodiments, the powder composition includes one or more ofdiethylene glycol methyl ether, diethylene glycol ethyl ether,diethylene glycol propyl ether, diethylene glycol n-butyl ether,diethylene glycol t-butyl ether, diethylene glycol pentyl ether,diethylene glycol hexyl ether, diethylene glycol heptyl ether,diethylene glycol octyl ether, diethylene glycol phenyl ether,diethylene glycol methyl ether acetate, diethylene glycol ethyl etheracetate, diethylene glycol propyl ether acetate, diethylene glycoln-butyl ether acetate, diethylene glycol t-butyl ether acetate,diethylene glycol pentyl ether acetate, diethylene glycol hexyl etheracetate, diethylene glycol heptyl ether acetate, diethylene glycol octylether acetate, diethylene glycol phenyl ether acetate, dipropyleneglycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycolpropyl ether, dipropylene glycol n-butyl ether, dipropylene glycolt-butyl ether, dipropylene glycol pentyl ether, dipropylene glycol hexylether, dipropylene glycol heptyl ether, dipropylene glycol octyl ether,dipropylene glycol phenyl ether, dipropylene glycol methyl etheracetate, dipropylene glycol ethyl ether acetate, dipropylene glycolpropyl ether acetate, dipropylene glycol n-butyl ether acetate,dipropylene glycol t-butyl ether acetate, dipropylene glycol pentylether acetate, dipropylene glycol hexyl ether acetate, dipropyleneglycol heptyl ether acetate, dipropylene glycol octyl ether acetate anddipropylene glycol phenyl ether acetate. In embodiments, the powdercomposition includes DGHE. In embodiments, the powder compositionincludes DGHE and one or more of diethylene glycol methyl ether,diethylene glycol ethyl ether, diethylene glycol propyl ether,diethylene glycol n-butyl ether, diethylene glycol t-butyl ether,diethylene glycol pentyl ether, diethylene glycol heptyl ether,diethylene glycol octyl ether, diethylene glycol phenyl ether,diethylene glycol methyl ether acetate, diethylene glycol ethyl etheracetate, diethylene glycol propyl ether acetate, diethylene glycoln-butyl ether acetate, diethylene glycol t-butyl ether acetate,diethylene glycol pentyl ether acetate, diethylene glycol hexyl etheracetate, diethylene glycol heptyl ether acetate, diethylene glycol octylether acetate, diethylene glycol phenyl ether acetate, dipropyleneglycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycolpropyl ether, dipropylene glycol n-butyl ether, dipropylene glycolt-butyl ether, dipropylene glycol pentyl ether, dipropylene glycol hexylether, dipropylene glycol heptyl ether, dipropylene glycol octyl ether,dipropylene glycol phenyl ether, dipropylene glycol methyl etheracetate, dipropylene glycol ethyl ether acetate, dipropylene glycolpropyl ether acetate, dipropylene glycol n-butyl ether acetate,dipropylene glycol t-butyl ether acetate, dipropylene glycol pentylether acetate, dipropylene glycol hexyl ether acetate, dipropyleneglycol heptyl ether acetate, dipropylene glycol octyl ether acetate anddipropylene glycol phenyl ether acetate.

In embodiments, the powder composition further includes a saltcontaining alkyl sulfate as described herein. In embodiments, the alkylsulfate salt may be represented as R³OSO₃M, where R³ represents aC₁-C₂₄, C₁₀-C₂₄, or C₁₂-C₂₀ alkyl or hydroxyalkyl radical and Mrepresents a cation selected from a metal cation, for example, alkalimetal cation or alkali-earth metal cation, or the ammonium cation (NH₄⁺). In embodiments, the salt includes a cation, such as ammonium ion(NH₄ ⁺), sodium ion (Na+), or calcium ion (Ca²⁺). In embodiments, thesalt includes lauryl sulfate. In embodiments, the salt includes sodiumlauryl sulfate (SDS).

In embodiments, the powder composition is subjected to hydration. Inembodiments, the powder composition is used for preparing a liquidfluid, for example, by adding water or aqueous components to the powdercomposition. In embodiments, the powder composition is used forpreparing a fracturing fluid, for example, by adding water or aqueouscomponents to the powder composition. In embodiments, the powdercomposition is used for preparing a slurry, for example, by adding wateror aqueous components to the powder composition. In embodiments, thepowder composition is used for preparing a proppant suspension, forexample, by adding water or aqueous components to the powdercomposition.

When the powder composition of the polymer hydrates in water, thepolymer chains may be released into the water which builds viscosity.The viscosity of the polymer solution increases with increasing degreeof hydration. For incomplete or low degree of hydration, one can alsosee incomplete hydrated particles or fish eyes in the system. Inembodiments, hydration rate of the composition when it is polymerized inthe polymer may be increased at low shear mixing (for example, less than10,000 rpm). In embodiments, hydration rate of the powder compositionwhen it is polymerized in the polymer may be increased at low shearmixing (for example, less than 10,000 rpm). In embodiments, the powdercomposition as being added with water or water component has a viscositymeasured at 511 S−1 of greater than about 10 cp, of greater than about15 cp, of greater than about 20 cp, of greater than about 25 cp, ofgreater than about 30 cp, of greater than about 35 cp, of greater thanabout 40 cp, of greater than about 45 cp, of greater than about 50 cp,of greater than about 55 cp, of greater than about 60 cp, of greaterthan about 65 cp, of greater than about 70 cp, of greater than about 75cp, or of greater than about 80 cp. In embodiments, when the 0.3 wt % ofthe polymer from the powder composition is added to water or watercomponent, a viscosity thereof measured at 511 S⁻¹ may be greater thanabout 10 cp, of greater than about 15 cp, of greater than about 20 cp,of greater than about 25 cp, of greater than about 30 cp, of greaterthan about 35 cp, of greater than about 40 cp, of greater than about 45cp, of greater than about 50 cp, or of greater than about 55 cp. Inother embodiments, when the 0.6 wt % of the polymer from the powdercomposition is added to water or water component, a viscosity thereofmeasured at 511 S⁻¹ may be greater than about 10 cp, of greater thanabout 15 cp, of greater than about 20 cp, of greater than about 25 cp,of greater than about 30 cp, of greater than about 35 cp, of greaterthan about 40 cp, of greater than about 45 cp, of greater than about 50cp, of greater than about 55 cp, of greater than about 60 cp, of greaterthan about 65 cp, of greater than about 70 cp, of greater than about 75cp, or of greater than about 80 cp.

In embodiments, the hydration rate of the powder composition isincreased at low shear mixing (for example, less than 10,000 rpm). Inembodiments, the dried polymer composition is combined with mineral oilbefore adding to water. In embodiments, dry polymer is pre-treated orpost-treated with a solvent (e.g. mutual solvent) before addition towater. In embodiments, a hydrating surfactant is incorporated duringpolymer manufacture. In embodiments, examples of hydrating surfactantsinclude, but are not limited to, EO/PO copolymers, e.g., ANTIAROX 31R1,ANTAROX LA EP 16 and ANTAROX BL 225 In embodiments, examples of solventsinclude, but are not limited to, ethylene glycol, propylene glycol,ethylene glycol monobutyl ether (EGMBE), and “green” solvents, e.g.RHODISOLV DIB.

In embodiments, the powder composition has a particle size of from about1 μm to about 10 mm. In embodiments, the powder composition has aparticle size of from about 1 μm to about 5 mm. In embodiments, thepowder composition has a particle size of from about 1 μm to about 1 mm.In embodiments, the powder composition has a particle size of from about1 μm to about 900 μm. In embodiments, the powder composition has aparticle size of from about 1 μm to about 800 μm. In embodiments, thepowder composition has a particle size of from about 1 μm to about 700μm. In embodiments, the powder composition has a particle size of fromabout 1 μm to about 600 μm. In embodiments, the powder composition has aparticle size of from about 1 μm to about 500 μm. In embodiments, thepowder composition has a particle size of from about 10 μm to about 500μm. In embodiments, the powder composition has a particle size of fromabout 50 μm to about 500 μm. In embodiments, the powder composition hasa particle size of from about 100 μm to about 500 μm. The “particlesize” as used herein is determined by a diameter of the particle that ismeasured along an axis to give the maximal length.

In embodiments, the power composition or a polymer powder as describedabove may be produced by using the composition described herein. Inembodiments, the method of manufacturing the polymer in powder formincludes the steps including combining the composition and water to forman aqueous polymer composition; synthesizing a polymer by polymerizingthe aqueous polymer composition; drying the polymer; and forming thepolymer powder from the dried polymer. In embodiments, the polymerpowder is formed by grinding or milling.

In some embodiments, the polymers, which may be prepared using thecomposition disclosed herein, may be prepared via micellarpolymerization. The polymer may be prepared by a polymeric systemincluding sequential copolymers (P), which include at least one chain(C) of the type obtained by micellar polymerization, for keeping solidparticles (p) in suspension in a fluid (F) where said chain (C) issoluble.

Within the meaning of the present description, the term “chain solublein the fluid (F)” is understood to mean a chain (C) which typically hasa solubility at 20° C. of greater than or equal to 0.5% (5,000 ppm),preferably of greater than or equal to 1%, in the fluid (F).

Micellar polymerization consists schematically in carrying out apolymerization of hydrophilic monomers in a hydrophilic medium includingmicelles including hydrophobic monomers. Examples of micellarpolymerization have in particular been described in U.S. Pat. No.4,432,881 or else in Polymer, Vol. 36, No. 16, pp. 3197-3211 (1996), towhich documents reference may be made for further details.

In embodiments, the chain (C) of the polymers (P) is a chain which issoluble overall in the fluid (F) and which is predominantly formed of aseries of hydrophilic units interrupted at different points by aplurality of hydrophobic sequences (B) of substantially identical size.The polymer of the present disclosure can be composed of the chain (C)or else can be a block copolymer where the chain (C) constitutes one ofthe blocks. In embodiments, the polymer further includes the glycerolether component in addition to the chain (C) or a block copolymer wherethe chain (C) constitutes one of the blocks. In embodiments, theglycerol ether component exists as embedded between the chains (C). Inembodiments, the glycerol ether component is presented surrounding thechains (C). In embodiments, the polymer includes the chain (C) anddiethylene glycol hexyl ether (DGHE).

The hydrophobic sequences (B) can be polymer sequences which areinsoluble in the fluid (F), typically having a solubility at 20° C. ofless than or equal to 0.1% (1,000 ppm) in the fluid (F).

The copolymers (P) including the abovementioned chain (C) are suitablefor keeping the solid particles (p) in suspension. They can be particlespresent within the subterranean formation and/or particles injectedwithin the subterranean formation, typically jointly with the copolymers(such as, for example, proppant particles). For example, the copolymersand the glycol ether component (e.g., DGHE) are suitable for keeping thesolid particles (p) in suspension. For instance, the particles presentwithin the subterranean formation and/or particles injected within thesubterranean formation, may be used jointly with the copolymers andDGHE.

Use may typically be made, according to the present disclosure, of amicellar polymerization, where the following are copolymerized(typically via the radical route) within an aqueous dispersing medium(typically water or a water/alcohol mixture): hydrophilic monomers inthe dissolved or dispersed state in said medium; and hydrophobicmonomers within surfactant micelles formed in said medium by introducingthis surfactant therein at a concentration above its critical micelleconcentration (cmc).

The content of hydrophobic monomers corresponding to the ratio of theweight of the hydrophobic monomers with respect to the total weight ofthe hydrophobic and hydrophilic monomers is greater than or equal to0.01%, preferably greater than 0.1%, indeed even greater than 0.2%, andless than or equal to 5%. Generally, the percentage of the hydrophobicunits in the chain (C) is of the same order, typically greater than orequal to 0.05%, preferably greater than 0.1%, indeed even greater than0.2%, and less than or equal to 5%.

In micellar polymerization, the hydrophobic monomers present in themicelles are said to be in “micellar solution”. The micellar solution towhich reference is made is a micro-heterogeneous system which isgenerally isotropic, optically transparent and thermodynamically stable.

It should be noted that a micellar solution of the type employed inmicellar polymerization should be distinguished from a microemulsion. Inparticular, in contrast to a microemulsion, a micellar solution isformed at any concentration exceeding the critical micelle concentrationof the surfactant employed, with the sole condition that the hydrophobicmonomer be soluble at least to a certain extent within the internalspace of the micelles. A micellar solution furthermore differs from anemulsion in the absence of homogeneous internal phase: the micellescontain a very small number of molecules (typically less than 1000,generally less than 500 and typically from 1 to 100, with most often 1to 50, monomers, and at most a few hundred surfactant molecules, when asurfactant is present) and the micellar solution generally has physicalproperties similar to those of the monomer-free surfactant micelles.Moreover, generally, a micellar solution is transparent with respect tovisible light, given the small size of the micelles, which does notresult in refraction phenomena, unlike the drops of an emulsion, whichrefract light and give it its characteristic cloudy or white appearance.

The micellar polymerization technique results in characteristicsequential polymers which each includes several hydrophobic blocks ofsubstantially the same size and where this size can be controlled.Specifically, given the confinement of the hydrophobic monomers withinthe micelles, each of the hydrophobic blocks includes substantially oneand the same defined number n_(H) of hydrophobic monomers, it beingpossible for this number n_(H) to be calculated as follows(Macromolecular Chem. Physics, 202, 8, 1384-1397, 2001):

n _(H) =N _(agg)·[M _(H)]/([surfactant]−cmc)

where:

N_(agg) is the aggregation number of the surfactant, which reflects thesurfactant number present in each micelle;

[M_(H)] is the molar concentration of hydrophobic monomer in the medium;

[surfactant] is the molar concentration of surfactant in the medium; and

cmc is the critical micelle (molar) concentration.

The micellar polymerization technique thus makes possible advantageouscontrol of the hydrophobic units introduced into the polymers formed,namely: overall control of the molar fraction of hydrophobic units inthe polymer (by adjusting the ratio of the concentrations of the twomonomers); and more specific control of the number of hydrophobic unitspresent in each of the hydrophobic blocks (by modifying the parametersinfluencing the n_(H) defined above).

The chain (C) overall soluble in the fluid (F), which is obtained bymicellar polymerization, includes: a hydrophilic component, composed ofthe hydrophilic monomers, which corresponds to a hydrophilic polymerchain which would have a solubility typically of greater than or equalto 1% (10,000 ppm) at 20° C. if it were introduced alone into the fluid(F), a hydrophobic component, composed of the hydrophobic sequences,each having a solubility typically of less than or equal to 0.1% (1 000ppm) at 20° C. in the fluid (F).

In many cases, the chain (C) can be described as a hydrophilic chainhaving the abovementioned solubility (at least 1%) to which pendanthydrophobic groups are grafted. In particular in this case, the chain(C) has overall a solubility at 20° C. in the fluid (F) which can remaingreater than or equal to 0.1%, indeed even 0.5%.

In some embodiments, the chain (C) is of the type obtained by a processincluding a stage (e) of micellar radical polymerization in which thefollowing are brought into contact, within an aqueous medium (M):hydrophilic monomers, dissolved or dispersed in said aqueous medium (M)(typically water or a water/alcohol mixture); hydrophobic monomers inthe form of a micellar solution, namely a solution containing, in thedispersed state within the medium (M), micelles including thesehydrophobic monomers (it being possible in particular for this dispersedstate to be obtained using at least one surfactant); at least oneglycerol ether component; and at least one radical polymerizationinitiator, this initiator typically being water-soluble orwater-dispersible.

In some embodiments, the chain (C) is of the type obtained by a processincluding a stage (E) of micellar radical polymerization in which thefollowing are brought into contact, within an aqueous medium (M):hydrophilic monomers, dissolved or dispersed in said aqueous medium (M)(typically water or a water/alcohol mixture); hydrophobic monomers inthe form of a micellar solution, namely a solution containing, in thedispersed state within the medium (M), micelles including thesehydrophobic monomers (it being possible in particular for this dispersedstate to be obtained using at least one surfactant); at least oneglycerol ether component; at least one radical polymerization initiator,this initiator typically being water-soluble or water-dispersible; andat least one radical polymerization control agent.

Stage (E) is similar to the abovementioned stage (e) but employs anadditional control agent. This stage, known under the name of“controlled-nature micellar radical polymerization”, has in particularbeen described in WO 2013/060741. All the alternative forms described inthis document can be used here.

Within the meaning of the present description, the term “radicalpolymerization control agent” is understood to mean a compound which iscapable of extending the lifetime of the growing polymer chains in apolymerization reaction and of conferring, on the polymerization, aliving or controlled nature. This control agent is typically areversible transfer agent as employed in controlled radicalpolymerizations denoted under the terminology RAFT or MADIX, whichtypically employ a reversible addition-fragmentation transfer process,such as those described, for example, in WO 96/30421, WO 98/01478, WO99/35178, WO 98/58974, WO 00/75207, WO 01/42312, WO 99/35177, WO99/31144, FR 2 794 464 or WO 02/26836.

In some embodiments, the radical polymerization control agent employedin stage (E) is a compound which includes a thiocarbonylthio —S(C═S)—group. Thus, for example, it can be a compound which includes a xanthategroup (carrying —SC═S—O— functional groups), for example a xanthate.Other types of control agent can be envisaged (for example of the typeof those employed in CRP or in ATRP).

In some embodiments, the control agent employed in stage (E) can be apolymer chain resulting from a controlled radical polymerization andcarrying a group which is capable of controlling a radicalpolymerization (polymer chain of “living” type, which is a type wellknown per se). Thus, for example, the control agent can be a polymerchain (such as hydrophilic or water-dispersible) functionalized at thechain end with a xanthate group or more generally including an —SC═S—group, for example obtained according to the MADIX technology.

Alternatively, the control agent employed in stage (E) is anon-polymeric compound carrying a group which ensures the control of theradical polymerization, in particular a thiocarbonylthio —S(C═S)— group.

According to a specific alternative form, the radical polymerizationcontrol agent employed in stage (E) is a polymer, advantageously anoligomer, having a water-soluble or water-dispersible nature andcarrying a thiocarbonylthio —S(C═S)— group, for example a xanthate—SC═S—O— group. This polymer, which is capable of acting both as controlagent for the polymerization and as monomer in stage (E), is alsodenoted by “prepolymer” in the continuation of the description.Typically, this prepolymer is obtained by radical polymerization ofhydrophilic monomers in the presence of a control agent carrying athiocarbonylthio —S(C═S)— group, for example a xanthate. Thus, forexample, according to an advantageous embodiment which is illustrated atthe end of the present description, the control agent employed in stage(E) can advantageously be a prepolymer carrying a thiocarbonylthio—S(C═S)— group, for example a xanthate —SC═S—O— group, obtained onconclusion of a stage (E⁰) of controlled radical polymerization prior tostage (E). In this stage (E⁰), hydrophilic monomers, advantageouslyidentical to those employed in stage (E); a radical polymerizationinitiator and a control agent carrying a thiocarbonylthio —S(C═S)—group, for example a xanthate, can typically be brought into contact.

The use of the abovementioned stage (E⁰) prior to stage (E) makes itpossible, schematically, to hydrophilize a large number of controlagents carrying thiocarbonylthio functional groups (for examplexanthates, which are rather hydrophobic by nature), by converting themfrom prepolymers which are soluble or dispersible in the medium (M) ofstage (E). In certain embodiments, a prepolymer synthesized in stage(E⁰) has a short polymer chain, for example including a series of lessthan 50 monomer units, indeed even less than 25 monomer units, forexample between 2 and 15 monomer units.

When stage (E) is employed, the polymers according to the presentdisclosure include chains (C) which have a “controlled” structure,namely that all the chains (C) present on the polymers havesubstantially the same size and the same structure. The chains (C)include in particular the blocks (B) substantially in the same numberand proportion.

The specific polymers (P) employed in the context of the presentdisclosure, due to the presence of the hydrophobic sequences in ahydrophilic polymer chain, turn out to provide a control effect on thefluid which is particularly effective: without wishing to be committedto a theory, it appears that the hydrophobic units within a hydrophilicchain and/or different hydrophilic chains have a tendency to associatewith one another.

In embodiments, the injected fluid (F) includes the polymers (P) butdoes not include solid particles (p), and it encounters said particles(p) within the subterranean formation subsequent to its injection. Theassociation between particles and polymers then takes place in situ.Such a fluid can, for example, be injected during a drilling operation,and the rock cuttings formed during the drilling then perform the roleof the particles (p) in situ.

According to an alternative variant, the injected fluid (F) includes,before the injection, at least a portion and generally all of theparticles (p) associated with the polymer (P), it being understood thatit can optionally encounter other particles (p) within the subterraneanformation.

Two forms can in particular be envisaged in this context:

Form 1: the polymers (P) and the particles (p) are mixed during theformulation of the fluid (F), on the site of operation or upstream,typically by adding the particles (p), in the dry state or optionally inthe dispersed state, to a composition comprising the polymers (P) insolution.

Form 2: the fluid (F) is manufactured, advantageously on the site ofoperation, from a composition (premix) prepared upstream (hereinafterdenoted by the term “blend”) comprising the polymers (P) and at least aportion of the particles (p), generally within a dispersing liquid. Inorder to form the fluid (F), this blend is mixed with the otherconstituents of the fluid (F).

In some embodiments, the polymers (P) associated with the particles (p)can be employed as dispersing and stabilizing agent for the dispersionof the particles (p), at the same time providing an effect of agent forcontrol of fluid loss.

The notion of “control of fluid loss” refers here to the inhibition ofthe effect of “fluid loss” observed when a fluid is injected underpressure within a subterranean formation: the liquid present in thefluid has a tendency to penetrate into the constituent rock of thesubterranean formation, which can damage the well, indeed even harm itsintegrity. When these fluids employed under pressure contain insolublecompounds (which is very often the case, in particular for oil cementgrouts or else drilling or fracturing fluids), the effect of fluid lossat the same time brings about risks of loss of control of the fluidsinjected an increase in the concentration of insoluble compounds of thefluid, which can result in an increase in viscosity, which affects themobility of the fluid.

In particular when the fluid (F) is a fracturing, cementing or drillingfluid, the presence of the copolymers (P) makes it possible to obtaincontrol of fluid loss by limiting, indeed even completely inhibiting,the escape of the fluid (F), typically water or an aqueous composition,into the subterranean formation where the extraction is carried out.

Various specific advantages and embodiments of the present disclosurewill now be described in more detail.

THE FLUID (F). The term “fluid” is understood to mean, within themeaning of the description, any homogeneous or non-homogeneous mediumcomprising a liquid or viscous vector which optionally transports aliquid or gelled dispersed phase and/or solid particles, said mediumbeing overall pumpable by means of the devices for injection underpressure used in the application under consideration.

The term “liquid or viscous vector” of the fluid (F) is understood tomean the fluid itself, or else the solvent, in the case where the fluidincludes dissolved compounds, and/or the continuous phase, in the casewhere the fluid includes dispersed elements (droplets of liquid orgelled dispersed phase, solid particles, and the like).

According to a highly suitable embodiment, the fluid (F) is an aqueousfluid. The term “aqueous” is understood here to mean that the fluidincludes water as liquid or viscous vector, either as sole constituentof the liquid or viscous vector or in combination with otherwater-soluble solvents.

In the case of the presence of solvents other than water in the liquidor viscous vector of the fluid (F), the water advantageously remains thepredominant solvent within the liquid or viscous vector, advantageouslypresent in a proportion of at least 50% by weight, indeed even of atleast 75% by weight, with respect to the total weight of the solvents inthe liquid or viscous vector.

In some aspects, the fluid (F) is selected from fresh water, sea water,brines, salt water, produced water, recycled water, industrial wastewater, waste water associated with oil production, and combinationsthereof.

THE PARTICLES (p). The notion of “particle” within the meaning underwhich it is employed in the present description is not confined to thatof individual particles. It more generally denotes solid entities whichcan be dispersed within a fluid, in the form of objects (individualparticles, aggregates, and the like) for which all the dimensions areless than 5 mm, preferably less than 2 mm, for example less than 1 mm.

The particles (p) can be chosen from: calcium carbonate or cement,silica or sand, ceramic, clay, barite, hematite, carbon black and/ortheir mixtures.

In embodiments, the particles (p) are sands or cement particles.

The Polymers (P).

Hydrophilic monomers. The chain (C) can typically include monomerschosen from:

-   -   a) carboxylic acids which are ethylenically unsaturated,        sulfonic acids and phosphonic acids, and/or its derivatives,        such as acrylic acid (AA), methacrylic acid, ethacrylic acid,        α-chloroacrylic acid, crotonic acid, maleic acid, maleic        anhydride, itaconic acid, citraconic acid, mesaconic acid,        glutaconic acid, aconitic acid, fumaric acid, monoethylenically        unsaturated dicarboxylic acid monoesters comprising from 1 to 3        and preferably from 1 to 2 carbon atoms, for example monomethyl        maleate, vinylsulfonic acid, (meth)allylsulfonic acid,        sulfoethyl acrylate, sulfoethyl methacrylate, sulfopropyl        acrylate, sulfopropyl methacrylate, 1-allyloxy-2-hydroylpropyl        sulfonate, 2-hydroxy-3-acryloyloxypropylsulfonic acid,        2-hydroxy-3-methacryloyloxypropylsulfonic acid, styrenesulfonic        acids, 2-acrylamido-2-methylpropanesulfonic acid,        vinylphosphonic acid, α-methylvinylphosphonic acid and        allylphosphonic acid;    -   b) esters of α,β-ethylenically unsaturated mono- and        dicarboxylic acids with C₂-C₃ alkanediols, for example        2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,        2-hydroxyethyl ethacrylate, 2-hydroxypropyl acrylate,        2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate,        3-hydroxypropyl methacrylate and polyalkylene glycol        (meth)acrylates;    -   c) α,β-ethylenically unsaturated monocarboxylic acid amides and        their N-alkyl and N,N-dialkyl derivatives, such as acrylamide,        methacrylamide, N-methyl(meth)acrylamide,        N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide,        N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide,        morpholinyl(meth)acrylamide, and methylolacrylamide (acrylamide        and N,N-dimethyl(meth)acrylamide prove to be in particular        advantageous);    -   d) N-vinyllactams and its derivatives, for example        N-vinylpyrrolidone or N-vinylpiperidone;    -   e) open-chain N-vinylamide compounds, for example        N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide,        N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide,        N-vinylpropionamide, N-vinyl-N-methylpropionamide and        N-vinylbutyramide;    -   f) esters of α,β-ethylenically unsaturated mono- and        dicarboxylic acids with aminoalcohols, for example        N,N-dimethylaminomethyl (meth)acrylate, N,N-dimethylaminoethyl        (meth)acrylate, N,N-diethylaminoethyl acrylate and        N,N-dimethylaminopropyl (meth)acrylate;    -   g) amides of α,β-ethylenically unsaturated mono- and        dicarboxylic acids with diamines comprising at least one primary        or secondary amino group, such as        N-[2-(dimethylamino)ethyl]acrylamide,        N-[2-(dimethylamino)ethyl]methacrylamide,        N-[3-(dimethylamino)propyl]acrylamide,        N-[3-(dimethylamino)propyl]methacrylamide,        N-[4-(dimethylamino)butyl]acrylamide and        N-[4-(dimethylamino)butyl]methacrylamide;    -   h) N-diallylamines, N,N-diallyl-N-alkylamines, their acid        addition salts and their quaternization products, the alkyl        employed here preferably being C₁-C₃ alkyl;    -   i) N,N-diallyl-N-methylamine and        N,N-diallyl-N,N-dimethylammonium compounds, for example the        chlorides and bromides;    -   j) nitrogenous heterocycles substituted with vinyl and allyl,        for example N-vinylimidazole, N-vinyl-2-methylimidazole,        heteroaromatic compounds substituted with vinyl and allyl, for        example 2- and 4-vinylpyridine, 2- and 4-allylpyridine, and        their salts;    -   k) sulfobetaines; and    -   l) the salts of the abovementioned monomers; the mixtures and        combinations of two or more of the monomers and/or their salts        mentioned above.

In embodiments, the hydrophilic monomers can in particular includeacrylic acid (AA).

In embodiments, exemplary hydrophilic monomers of the chain (C) include(and typically consist of) (meth)acrylamide monomers, or more generally(meth)acrylamido monomers, including:

-   -   a) acrylamido monomers, namely acrylamide (Am),        dimethylacrylamide (DMA), its sulfonate derivative, in        particular acrylamidomethylpropanesulfonic acids (AMPS);    -   b) the quaternary ammonium APTAC and        sulfopropyldimethylammoniopropylacrylamide; and    -   c) methacrylamido monomers, such as        sulfopropyldimethylammoniopropylmethacrylamide (SPP) or        sulfohydroxypropyldimethylammoniopropylmethacrylamide.

In some embodiments, the hydrophilic monomers of the chain (C) areacrylamides. An acrylamide is preferably an acrylamide which is notstabilized with copper.

In some embodiments, the hydrophilic monomers of the chain (C) arechosen from acrylamides, dimethylacrylamides (DMA),acrylamidomethylpropanesulfonic acids (AMPS), acrylic acids (AA), theirsalts and their mixtures.

In embodiments, the hydrophilic monomers of the chain (C) can typicallyhave a polymerizable functional group of acrylamido type and a sidechain composed of ethylene oxide or propylene oxide strings, or elsebased on N-isopropylacrylamide or N-vinylcaprolactam.

Hydrophobic monomers. Nonlimiting examples of hydrophobic monomersconstituting the insoluble blocks may include:

-   -   a) vinylaromatic monomers, such as styrene, α-methylstyrene,        para-chloromethylstyrene, vinyltoluene, 2-methylstyrene,        4-methylstyrene, 2-(n-butyl)styrene, 4-(n-decyl)styrene or        tert-butyl styrene;    -   b) halogenated vinyl compounds, such as vinyl or vinylidene        halides, for example vinyl or vinylidene chlorides or fluorides,        corresponding to the formula R^(b)R^(c)C═CX¹X², where X¹═F or        Cl; X²═H, F or Cl; each one of R^(b) and R^(c) represents,        independently H, Cl, F or an alkyl group, preferably chlorinated        and/or fluorinated, more advantageously perchlorinated or        perfluorinated;    -   c) esters of α,β-ethylenically unsaturated mono- or dicarboxylic        acid with C₂-C₃₀ alkanols, for example methyl ethacrylate, ethyl        (meth)acrylate, ethyl ethacrylate, n-propyl (meth)acrylate,        isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl        (meth)acrylate, tert-butyl (meth)acrylate, tert-butyl        ethacrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate,        n-octyl (meth)acrylate, 1,1,3,3-tetramethylbutyl (meth)acrylate,        ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl        (meth)acrylate, n-undecyl (meth)acrylate, tridecyl        (meth)acrylate, myristyl (meth)acrylate, pentadecyl        (meth)acrylate, palmityl (meth)acrylate, heptadecyl        (meth)acrylate, nonadecyl (meth)acrylate, arachidyl        (meth)acrylate, behenyl (meth)acrylate, lignoceryl        (meth)acrylate, cerotinyl (meth)acrylate, melissinyl        (meth)acrylate, palmitoleoyl (meth)acrylate, oleyl        (meth)acrylate, linoleyl (meth)acrylate, linolenyl        (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate,        cetyl (meth)acrylate, erucyl (meth)acrylate, and their mixtures;    -   d) esters of vinyl or allyl alcohol with C₁-C₃₀ monocarboxylic        acids, for example vinyl formate, vinyl acetate, vinyl        propionate, vinyl butyrate, vinyl laurate, vinyl stearate, vinyl        propionate, vinyl versatate and their mixtures;    -   e) ethylenically unsaturated nitriles, such as acrylonitrile,        methacrylonitrile and their mixtures;    -   f) esters of α,β-ethylenically unsaturated mono- and        dicarboxylic acids with C₃-C₃₀ alkanediols, for example        3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate,        4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate,        6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate,        3-hydroxy-2-ethylhexyl acrylate and 3-hydroxy-2-ethylhexyl        methacrylate, and the like;    -   g) primary amides of α,β-ethylenically unsaturated mono- and        dicarboxylic acids and N-alkyl and N,N-dialkyl derivatives, such        as N-propyl(meth)acrylamide, N-(n-butyl)(meth)acrylamide,        N-(tert-butyl)(meth)acrylamide, N-butylphenylacrylamide,        N-methyl-N-hexylacrylamide, N,N-dihexylacrylamide,        hexyl(meth)acrylamide, N-(n-octyl)(meth)acrylamide,        N-(1,1,3,3-tetramethylbutyl)(meth)acrylamide,        N-ethylhexyl(meth)acrylamide, N-(n-nonyl)(meth)acrylamide,        N-(n-decyl)(meth)acrylamide, N-(n-undecyl)(meth)acrylamide,        N-tridecyl(meth)acrylamide, N-myristyl(meth)acrylamide,        N-pentadecyl(meth)acrylamide, N-palmityl(meth)acrylamide,        N-heptadecyl(meth)acrylamide, N-nonadecyl(meth)acrylamide,        N-arachidyl(meth)acrylamide, N-behenyl(meth)acrylamide,        N-lignoceryl(meth)acrylamide, N-cerotinyl(meth)acrylamide,        N-melissinyl(meth)acrylamide, N-palmitoleoyl(meth)acrylamide,        N-oleyl(meth)acrylamide, N-linoleyl(meth)acrylamide,        N-linolenyl(meth)acrylamide, N-stearyl(meth)acrylamide and        N-lauryl(meth)acrylamide;    -   h) N-vinyllactams and its derivatives, such as        N-vinyl-5-ethyl-2-pyrrolidone, N-vinyl-6-methyl-2-piperidone,        N-vinyl-6-ethyl-2-piperidone, N-vinyl-7-methyl-2-caprolactam and        N-vinyl-7-ethyl-2-caprolactam, and the like;    -   i) esters of α,β-ethylenically unsaturated mono- and        dicarboxylic acids with aminoalcohols, for example        N,N-dimethylaminocyclohexyl (meth)acrylate;    -   j) amides of α,β-ethylenically unsaturated mono- and        dicarboxylic acids with diamines comprising at least one primary        or secondary amino group, for example        N-[4-(dimethylamino)butyl]acrylamide,        N-[4-(dimethylamino)butyl]methacrylamide,        N-[2-(dimethylamino)ethyl]acrylamide,        N-[4-(dimethylamino)cyclohexyl]acrylamide,        N-[4-(dimethylamino)cyclohexyl]methacrylamide, and the like; and    -   k) monoolefins (C₂-C₈) and nonaromatic hydrocarbons comprising        at least two conjugated double bonds, for example ethylene,        propylene, isobutylene, isoprene, butadiene, and the like.

In embodiments, the hydrophobic monomers can be selected from:

-   -   a) C₁-C₃₀ alkyl and preferably C₄-C₂₂ alkyl α,β-unsaturated        esters, in particular alkyl acrylates and methacrylates, such as        methyl, ethyl, butyl, 2-ethylhexyl, isooctyl, lauryl, isodecyl,        stearyl, octyl, myristyl, pentadecyl, cetyl, oleyl or erucyl        acrylates and methacrylates (lauryl methacrylate in particular        proves to be especially advantageous);    -   b) C₁-C₃₀ alkyl and preferably C₄-C₂₂ alkyl α,β-unsaturated        amides, in particular alkylacrylamides and alkylmethacrylamides,        such as methyl-, ethyl-, butyl-, 2-ethylhexyl-, isooctyl-,        lauryl-, isodecyl-, stearyl-, octyl-, myristyl-, pentadecyl-,        cetyl-, oleyl- or erucylacrylamide or -methacrylamide        (laurylmethacrylamide in particular proves to be especially        advantageous);    -   c) vinyl or allyl alcohol esters of saturated carboxylic acids,        such as vinyl or allyl acetate, propionate, versatate or        stearate; and    -   d) α,β-unsaturated nitriles comprising from 3 to 12 carbon        atoms, such as acrylonitrile or methacrylonitrile; α-olefins and        conjugated dienes; vinylaromatic monomers, such as styrene,        α-methylstyrene, para-chloromethylstyrene, vinyltoluene,        2-methylstyrene, 4-methylstyrene, 2-(n-butyl)styrene,        4-(n-decyl)styrene or tert-butylstyrene; the mixtures and        combinations of two or more of the abovementioned monomers.

In embodiments, in particular when the fluid (F) is a fracturing fluid,use may be made of hydrophobic monomers which bond feebly to the chain(C). This makes it possible, if necessary, to remove the polymersintroduced within the subterranean formation (in view of theiramphiphilic nature, the polymers generally have a self-associativenature and tend to form gels which are difficult to remove; under theeffect in particular of the temperature and/or the pH, it is possible tocleave the hydrophobic monomers if they are not bonded excessivelystrongly to the polymer, which makes possible removal from the fluid).Hydrophobic monomers suited to this embodiment are in particular theabovementioned esters.

It should be noted that, when other monomers are used, removal from thefluids is still possible by a technique known per se, where “breakers”,such as oxidizing agents, are added. The preceding embodiment makes itpossible to dispense with the use of such “breakers”, which is reflectedin particular in terms of decrease in cost. In embodiments, the breakeris selected from peroxides, persulfates, peracids, bromates, chlorates,chlorites, and combinations thereof.

In some embodiments, the polymer can exhibit a molecular weight of fromabout 5,000 g/mol to about 20,000,000 g/mol. In other embodiments, themolecular weight of the polymer ranges from about 100,000 g/mol to about10,000,000 g/mol. In yet other embodiments, the molecular weight of thepolymer ranges from about 500,000 g/mol to about 5,000,000 g/mol.

THE RADICAL POLYMERIZATION AGENT. The control agent employed in stage(E) or, if appropriate, in stage (E⁰) of the process of the presentdisclosure is advantageously a compound carrying a thiocarbonylthio—S(C═S)— group. In embodiments, the control agent can carry severalthiocarbonylthio groups. It can optionally be a polymer chain carryingsuch a group.

Thus, this control agent can, for example, correspond to the formula (A)below:

in which Z represents: a hydrogen atom, a chlorine atom, an optionallysubstituted alkyl or optionally substituted aryl radical, an optionallysubstituted heterocycle, an optionally substituted alkylthio radical, anoptionally substituted arylthio radical, an optionally substitutedalkoxy radical, an optionally substituted aryloxy radical, an optionallysubstituted amino radical, an optionally substituted hydrazine radical,an optionally substituted alkoxycarbonyl radical, an optionallysubstituted aryloxycarbonyl radical, an optionally substituted acyloxyor carboxyl radical, an optionally substituted aroyloxy radical, anoptionally substituted carbamoyl radical, a cyano radical, a dialkyl- ordiarylphosphonato radical, a dialkyl-phosphinato or diaryl-phosphinatoradical, or a polymer chain, and R⁴ represents an optionally substitutedalkyl, acyl, aryl, aralkyl, alkenyl or alkynyl group, a saturated orunsaturated, aromatic, optionally substituted carbocycle or heterocycle,or a polymer chain, which can be hydrophilic or water-dispersible whenthe agent is employed in stage (E).

The R⁴ or Z groups, when they are substituted, can be substituted byoptionally substituted phenyl groups, optionally substituted aromaticgroups, saturated or unsaturated carbocycles, saturated or unsaturatedheterocycles, or groups selected from the following: alkoxycarbonyl oraryloxycarbonyl (—COOR), carboxyl (—COOH), acyloxy (—O₂CR), carbamoyl(—CONR), cyano (—CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl,arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino,guanidimo, hydroxyl (—OH), amino (—NR), halogen, perfluoroalkylC_(n)F_(2n+1), allyl, epoxy, alkoxy (—OR), S-alkyl, S-aryl, groupsexhibiting a hydrophilic or ionic nature, such as alkali metal salts ofcarboxylic acids, alkali metal salts of sulfonic acids, polyalkyleneoxide (PEO, PPO) chains, cationic substituents (quaternary ammoniumsalts), R representing an alkyl or aryl group, or a polymer chain.

For the control agents of formula (A) employed in stage (E), it isgenerally preferred for the R⁴ group to be of hydrophilic nature.Advantageously, it is a water-soluble or water-dispersible polymerchain.

The R⁴ group can alternatively be amphiphilic, namely exhibit both ahydrophilic and a lipophilic nature. It is preferable for R₁ not to behydrophobic.

As regards the control agents of formula (A) employed in stage (E⁰), R⁴can typically be a substituted or unsubstituted, preferably substituted,alkyl group. A control agent of formula (A) employed in stage (E⁰) cannevertheless include other types of R⁴ groups, in particular a ring or apolymer chain.

The optionally substituted alkyl, acyl, aryl, aralkyl or alkynyl groupsgenerally exhibit from 1 to 20 carbon atoms, preferably from 1 to 12 andmore preferably from 1 to 9 carbon atoms. They can be linear orbranched. They can also be substituted by oxygen atoms, in particular inthe form of esters, sulfur atoms or nitrogen atoms.

Mention may in particular be made, among the alkyl radicals, of themethyl, ethyl, propyl, butyl, pentyl, isopropyl, tert-butyl, pentyl,hexyl, octyl, decyl or dodecyl radical.

The alkyne groups are radicals generally of 2 to 10 carbon atoms; theyexhibit at least one acetylenic unsaturation, such as the acetylenylradical.

The acyl group is a radical generally exhibiting from 1 to 20 carbonatoms with a carbonyl group.

Mention may in particular be made, among the aryl radicals, of thephenyl radical, which is optionally substituted, in particular by anitro or hydroxyl functional group.

Mention may in particular be made, among the aralkyl radicals, of thebenzyl or phenethyl radical, which is optionally substituted, inparticular by a nitro or hydroxyl functional group.

When R⁴ or Z is a polymer chain, this polymer chain can result from aradical or ionic polymerization or from a polycondensation.

Advantageously, use is made, as control agent for stage (E) and also forstage (E⁰), if appropriate, of compounds carrying a xanthate —S(C═S)O—,trithiocarbonate, dithiocarbamate or dithiocarbazate functional group,for example carrying an O-ethyl xanthate functional group of formula—S(C═S)OCH₂CH₃.

When stage (E⁰) is carried out, it is in particular advantageous toemploy, as control agents in this stage, a compound chosen fromxanthates, trithiocarbonates, dithiocarbamates and dithiocarbazates.Xanthates prove to be very particularly advantageous, in particularthose carrying an O-ethyl xanthate —S(C═S)OCH₂CH₃ functional group, suchas O-ethyl S-(1-(methoxycarbonyl)ethyl) xanthate(CH₃CH(CO₂CH₃))S(C═S)OEt. Another possible control agent in stage (E⁰)is dibenzyl trithiocarbonate of formula PhCH₂S(C═S)SCH₂Ph (wherePh=phenyl).

The living prepolymers obtained in step (E⁰) by using the abovementionedcontrol agents prove to be particularly advantageous for carrying outstage (E).

Initiation and Implementation of the Radical Polymerizations of Stages(E) and (E⁰). When it is employed in stage (E), the radicalpolymerization initiator can be water-soluble or water-dispersible.Apart from this preferential condition, any radical polymerizationinitiator (source of free radicals) known per se and suited to theconditions chosen for these stages can be employed in stage (E) andstage (E⁰) of the disclosed process.

Thus, the radical polymerization initiator employed according to thepresent disclosure can, for example, be chosen from the initiatorsconventionally used in radical polymerization. It can, for example, beone of the following initiators:

-   -   a) hydrogen peroxides, such as: tert-butyl hydroperoxide, cumene        hydroperoxide, t-butyl peroxyacetate, t-butyl peroxybenzoate,        t-butyl peroxyoctoate, t-butyl peroxyneodecanoate, t-butyl        peroxyisobutyrate, lauroyl peroxide, t-amyl peroxypivalate,        t-butyl peroxypivalate, dicumyl peroxide, benzoyl peroxide,        potassium persulfate or ammonium persulfate,    -   b) azo compounds, such as: 2,2′-azobis(isobutyronitrile),        2,2′-azobis(2-butanenitrile), 4,4′-azobis(4-pentanoic acid),        1,1′-azobis(cyclohexanecarbonitrile),        2-(t-butylazo)-2-cyanopropane,        2,2′-azobis[2-methyl-N-(1,1)-bis(hydroxymethyl)-2-hydroxyethyl]propionamide,        2,2′-azobis(2-methyl-N-hydroxyethyl]propionamide,        2,2′-azobis(N,N′-dimethyleneisobutyramidine) dichloride,        2,2′-azobis(2-amidinopropane) dichloride,        2,2′-azobis(N,N′-dimethyleneisobutyramide),        2,2′-azobis(2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide),        2,2′-azobis(2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide),        2,2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide] or        2,2′-azobis(isobutyramide) dihydrate,    -   c) redox systems comprising combinations, such as:    -   d) mixtures of hydrogen peroxide, alkyl peroxide, peresters,        percarbonates and the like and any iron salt, titanous salt,        zinc formaldehyde sulfoxylate or sodium formaldehyde        sulfoxylate, and reducing sugars,    -   e) alkali metal or ammonium persulfates, perborates or        perchlorates in combination with an alkali metal bisulfite, such        as sodium metabisulfite, and reducing sugars, and    -   f) alkali metal persulfates in combination with an        arylphosphinic acid, such as benzenephosphonic acid and the        like, and reducing sugars.

Typically, the amount of initiator to be used can be determined so thatthe amount of radicals generated is at most 50 mol % and preferably atmost 20 mol %, with respect to the amount of control or transfer agent.

Very particularly in stage (E), it generally proves to be advantageousto use a radical initiator of redox type, which exhibits, inter alia,the advantage of not requiring heating of the reaction medium (nothermal initiation), and the inventors of which have in addition nowdiscovered that it proves to be suitable for the micellar polymerizationof stage (E).

Thus, the radical polymerization initiator employed in stage (E) cantypically be a redox initiator, typically not requiring heating for itsthermal initiation. It is typically a mixture of at least one oxidizingagent with at least one reducing agent.

The oxidizing agent present in this redox system can be a water-solubleagent. This oxidizing agent can, for example, be chosen from peroxides,such as: hydrogen peroxide, tert-butyl hydroperoxide, cumenehydroperoxide, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butylperoxyoctoate, t-butyl peroxyneodecanoate, t-butyl peroxyisobutyrate,lauroyl peroxide, t-amyl peroxypivalate, t-butyl peroxypivalate, dicumylperoxide, benzoyl peroxide, sodium persulfate, potassium persulfate,ammonium persulfate or also potassium bromate.

The reducing agent present in the redox system can also be awater-soluble agent. This reducing agent can typically be chosen fromsodium formaldehyde sulfoxylate (in particular in its dihydrate form,known under the name Rongalit, or in the form of an anhydride), ascorbicacid, erythorbic acid, sulfites, bisulfites or metasulfites (inparticular alkali metal sulfites, bisulfites or metasulfites),nitrilotrispropionamides, and tertiary amines and ethanolamines (whichcan be water-soluble).

Possible redox systems include combinations, such as:

-   -   a) mixtures of water-soluble persulfates with water-soluble        tertiary amines,    -   b) mixtures of water-soluble bromates (for example, alkali metal        bromates) with water-soluble sulfites (for example, alkali metal        sulfites),    -   c) mixtures of hydrogen peroxide, alkyl peroxide, peresters,        percarbonates and the like and any iron salt, titanous salt,        zinc formaldehyde sulfoxylate or sodium formaldehyde        sulfoxylate, and reducing sugars,    -   d) alkali metal or ammonium persulfates, perborates or        perchlorates in combination with an alkali metal bisulfite, such        as sodium metabisulfite, and reducing sugars, and    -   e) alkali metal persulfates in combination with an        arylphosphinic acid, such as benzenephosphonic acid and the        like, and reducing sugars.

An advantageous redox system includes (and preferably consists of) thecombination of ammonium persulfate and sodium formaldehyde sulfoxylate.

Generally, and in particular in the case of the use of a redox system ofthe ammonium persulfate/sodium formaldehyde sulfoxylate type, it provesto be preferable for the reaction medium of stage (E) to be devoid ofcopper. In the case of the presence of copper, it is generally desirableto add a copper-complexing agent, such as EDTA, in an amount capable ofmasking its presence.

Whatever the nature of the initiator employed, the radicalpolymerization of stage (E⁰) can be carried out in any appropriatephysical form, for example in solution in water or in a solvent, forexample an alcohol or THF, in emulsion in water (“latex” process) or inbulk, if appropriate while controlling the temperature and/or the pH inorder to render entities liquid and/or soluble or insoluble.

After carrying out stage (E), given the specific use of a control agent,polymers functionalized with transfer groups (living polymers) areobtained. This living character makes it possible, if desired, to employthese polymers in a subsequent polymerization reaction, according to atechnique well known per se. Alternatively, if required, it is possibleto deactivate or to destroy the transfer groups, for example byhydrolysis, ozonolysis or reaction with amines, according to means knownper se. Thus, the disclosed process can include, after stage (E), astage (E1) of hydrolysis, of ozonolysis or of reaction with amines whichis capable of deactivating and/or destroying all or a portion of thetransfer groups present on the polymer prepared in stage (E).

Surfactants. Use may be made, in order to prepare the micellar solutionof the hydrophobic monomers which are employed in stage (E), of anysuitable surfactant in a nonlimiting manner; use may be made, forexample, of the surfactants chosen from the following list.

Anionic surfactants can be chosen from:

-   -   a) alkyl ester sulfonates, for example of formula        R—CH(SO₃M)-CH₂COOR′, or alkyl ester sulfates, for example of        formula R—CH(OSO₃M)-CH₂COOR′, where R represents a C₈-C₂₀ and        preferably C₁₀-C₁₆ alkyl radical, R′ represents a C₁-C₆ and        preferably C₁-C₃ alkyl radical and M represents an alkali metal        cation, for example the sodium cation, or the ammonium cation.        Mention may very particularly be made of methyl ester        sulfonates, the R radical of which is a C₁₄-C₁₆ radical;    -   b) alkylbenzenesulfonates, more particularly C₉-C₂₀        alkylbenzenesulfonates, primary or secondary alkylsulfonates, in        particular C₈-C₂₂ alkylsulfonates, or alkylglycerolsulfonates;    -   c) alkyl sulfates, for example of formula ROSO₃M, where R        represents a C₁₀-C₂₄ and preferably C₁₂-C₂₀ alkyl or        hydroxyalkyl radical and M represents a cation with the same        definition as above;    -   d) alkyl ether sulfates, for example of formula RO(OA)_(n)SO₃M,        where R represents a C₁₀-C₂₄ and preferably C₁₂-C₂₀ alkyl or        hydroxyalkyl radical, OA represents an ethoxylated and/or        propoxylated group, M represents a cation with the same        definition as above and n generally varies from 1 to 4, such as,        for example, lauryl ether sulfate with n=2;    -   e) alkylamide sulfates, for example of formula RCONHR′OSO₃M,        where R represents a C₂-C₂₂ and preferably C₆-C₂₀ alkyl radical,        R′ represents a C₂-C₃ alkyl radical and M represents a cation        with the same definition as above, and also their        polyalkoxylated (ethoxylated and/or propoxylated) derivatives        (alkylamide ether sulfates);    -   f) salts of saturated or unsaturated fatty acids, for example        such as C₈-C₂₄ and preferably C₁₄-C₂₀ acids, and of an alkaline        earth metal cation, N-acyl-N-alkyltaurates, alkylisethionates,        alkylsuccinamates and alkyl sulfosuccinates, alkylglutamates,        monoesters or diesters of sulfosuccinates, N-acylsarcosinates or        polyethoxycarboxylates;    -   g) monoester and diester phosphates, for example having the        following formula: (RO)_(x)—P(═O)(OM)_(x), where R represents an        optionally polyalkoxylated alkyl, alkylaryl, arylalkyl or aryl        radical, x and x′ are equal to 1 or 2, provided that the sum of        x and x′ is equal to 3, and M represents an alkaline earth metal        cation;

Nonionic surfactants can be chosen from alkoxylated fatty alcohols, forexample laureth-2, laureth-4, laureth-7 or oleth-20, alkoxylatedtriglycerides, alkoxylated fatty acids, alkoxylated sorbitan esters,alkoxylated fatty amines, alkoxylated di(1-phenylethyl)phenols,alkoxylated tri(1-phenylethyl)phenols, alkoxylated alkylphenols, theproducts resulting from the condensation of ethylene oxide with ahydrophobic compound resulting from the condensation of propylene oxidewith propylene glycol, such as the Pluronic products sold by BASF, theproducts resulting from the condensation of ethylene oxide the compoundresulting from the condensation of propylene oxide with ethylenediamine,such as the Tetronic products sold by BASF, alkylpolyglycosides, such asthose described in U.S. Pat. No. 4,565,647, or alkylglucosides, or fattyacid amides, for example C₈-C₂₀ fatty acid amides, in particular fattyacid monoalkanolamides, for example cocamide MEA or cocamide MIPA.

Amphoteric surfactants (true amphoteric entities comprising an ionicgroup and a potentially ionic group of opposite charge, or zwitterionicentities simultaneously comprising two opposite charges) can be betainesgenerally, in particular carboxybetaines, for example lauryl betaine(Mirataine BB from Rhodia) or octyl betaine or coco betaine (MirataineBB-FLA from Rhodia); amidoalkyl betaines, such as cocamidopropyl betaine(CAPB) (Mirataine BDJ from Rhodia or Mirataine BET C-30 from Rhodia);sulfobetaines or sultaines, such as cocamidopropyl hydroxysultaine(Mirataine CBS from Rhodia); alkylamphoacetates andalkylamphodiacetates, such as, for example, comprising a cocoyl orlauryl chain (Miranol C2M Conc. NP, C32, L32 in particular, fromRhodia); alkylamphopropionates or alkylamphodipropionates (Miranol C2MSF); alkyl amphohydroxypropyl sultaines (Miranol CS); alkylamine oxides,for example lauramine oxide (INCI).

Cationic surfactants can be optionally polyethoxylated primary,secondary or tertiary fatty amine salts, quaternary ammonium salts, suchas tetraalkylammonium, alkylamidoalkylammonium, trialkylbenzylammonium,trialkylhydroxyalkylammonium or alkylpyridinium chlorides or bromides,imidazoline derivatives or amine oxides having a cationic nature. Anexample of a cationic surfactant is cetrimonium chloride or bromide(INCI);

In embodiments, the surfactants can be block copolymers comprising atleast one hydrophilic block and at least one hydrophobic block differentfrom the hydrophilic block, which are advantageously obtained accordingto a polymerization process where:

-   -   (a₀) at least one hydrophilic (respectively hydrophobic)        monomer, at least one source of free radicals and at least one        radical polymerization control agent of the —S(C═S)— type are        brought together within an aqueous phase;    -   (a₁) the polymer obtained on conclusion of stage (a₀) is brought        into contact with at least one hydrophobic (respectively        hydrophilic) monomer different from the monomer employed in        stage (a₀) and at least one source of free radicals; via which a        diblock copolymer is obtained.

Polymers of the triblock type, or comprising more blocks, can optionallybe obtained by carrying out, after stage (a₁), a stage (a₂) in which thepolymer obtained on conclusion of stage (a₁) is brought into contactwith at least one monomer different from the monomer employed in stage(a₁) and at least one source of free radicals; and more generally bycarrying out (n+1) stages of the type of the abovementioned stages (a₁)and (a₂) and n is an integer typically ranging from 1 to 3, where, ineach stage (a_(n)), with n≥1, the polymer obtained on conclusion ofstage (a_(n−1)) is brought into contact with at least one monomerdifferent from the monomer employed in stage (a_(n−1)) and at least onesource of free radicals. Use may be made, for example, according to thepresent disclosure, of the copolymers of the type which are described inWO03068827, WO03068848 and WO2005/021612.

In embodiments, one or more polymers of the present disclosure arepresent in an aqueous composition. In embodiments, one or more polymersof the present disclosure are present in an aqueous composition in anamount ranging from about 0.001 wt % to about 10 wt % based upon thetotal weight of the aqueous composition.

In embodiments, hydration rate of the powder polymers of the presentdisclosure is increased at low shear mixing (for example, less than10,000 rpm). In embodiments, dry polymer is combined with mineral oilbefore adding to water. In embodiments, dry polymer is pre-treated orpost-treated with a solvent (e.g. mutual solvent) before addition towater. In embodiments, a hydrating surfactant is incorporated duringpolymer manufacture. In embodiments, examples of hydrating surfactantsinclude, but are not limited to, EO/PO copolymers, e.g., ANTAROX 31R1,ANTAROX LA EP 16 and ANTAROX BL 225. In some embodiments, examples ofsolvents include, but are not limited to, ethylene glycol, propyleneglycol, ethylene glycol monobutyl ether (EGMBE), and “green” solvents,e.g. RHODISOLV DIB.

Methods

In an aspect, methods for utilizing the present polymers and relatedcompositions are provided. In embodiments, the method of utilizing thepolymer may include using a slurry including the polymer and an aqueouscomponent; and a proppant.

In embodiments, the slurry includes a polymer and an aqueous component;and a proppant. In embodiments, the polymer includes

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof; ii) at least one hydrophilicmonomer selected from acrylate, acrylate salts, acrylamide,2-acrylamido-2-methylpropane sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid salts, and combinations thereof; and

iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.

In embodiments, the polymer has a hydration rate of about 10% orgreater, about 15% or greater, about 20% or greater, about 25% orgreater, about 30% or greater, about 35% or greater, about 40% orgreater, about 45% or greater, about 50% or greater, about 55% orgreater, about 60% or greater, about 65% or greater, about 70% orgreater, about 75% or greater, about 80% or greater, about 85% orgreater, about 90% or greater, about 95% or greater, or about 99% orgreater. In embodiments, the polymer has a hydration rate of about 70%or greater.

In embodiments, the aqueous component is selected from distilled water,fresh water, sea water, brines, salt water, produced water, recycledwater, industrial waste water, waste water associated with oilproduction, and combinations thereof.

In embodiments, the glycol ether is selected from diethylene glycolmethyl ether, diethylene glycol ethyl ether, diethylene glycol propylether, diethylene glycol n-butyl ether, diethylene glycol t-butyl ether,diethylene glycol pentyl ether, diethylene glycol hexyl ether,diethylene glycol heptyl ether, diethylene glycol octyl ether,diethylene glycol phenyl ether, diethylene glycol methyl ether acetate,diethylene glycol ethyl ether acetate, diethylene glycol propyl etheracetate, diethylene glycol n-butyl ether acetate, diethylene glycolt-butyl ether acetate, diethylene glycol pentyl ether acetate,diethylene glycol hexyl ether acetate, diethylene glycol heptyl etheracetate, diethylene glycol octyl ether acetate, diethylene glycol phenylether acetate, dipropylene glycol methyl ether, dipropylene glycol ethylether, dipropylene glycol propyl ether, dipropylene glycol n-butylether, dipropylene glycol t-butyl ether, dipropylene glycol pentylether, dipropylene glycol hexyl ether, dipropylene glycol heptyl ether,dipropylene glycol octyl ether, dipropylene glycol phenyl ether,dipropylene glycol methyl ether acetate, dipropylene glycol ethyl etheracetate, dipropylene glycol propyl ether acetate, dipropylene glycoln-butyl ether acetate, dipropylene glycol t-butyl ether acetate,dipropylene glycol pentyl ether acetate, dipropylene glycol hexyl etheracetate, dipropylene glycol heptyl ether acetate, dipropylene glycoloctyl ether acetate, dipropylene glycol phenyl ether acetate, andcombinations thereof. In embodiments, the glycol ether is diethyleneglycol hexyl ether (DGHE).

In embodiments, the slurry is included various polymeric systems thatare utilized in connection with subterranean formations. In the presentdescription, the notion of “subterranean formation” is understood in itsbroadest sense and includes both a rock containing hydrocarbons, inparticular oil, and the various rock layers traversed in order to accessthis oil-bearing rock and to ensure the extraction of the hydrocarbons.Within the meaning of the present description, the notion of “rock” isused to denote any type of constituent material of a solid subterraneanformation, whether or not the material constituting it is strictlyspeaking a rock. Thus, in particular, the expression “oil-bearing rock”is employed here as synonym for “oil-bearing reservoir” and denotes anysubterranean formation containing hydrocarbons, in particular oil,whatever the nature of the material containing these hydrocarbons (rockor sand, for example).

Mention may in particular be made, among the fluids injected underpressure into subterranean formations, of the various fluids forcompletion and workover of the wells, in particular drilling fluids,whether they are used to access the oil-bearing rock or else to drillthe reservoir itself (“drill-in”), or else fracturing fluids, oralternatively completion fluids, control or workover fluids or annularfluids or packer fluids or spacer fluids or acidizing fluids, or alsofluids for cementing.

More specifically, according to some aspects, a subject-matter of thepresent disclosure is the use of the abovementioned sequentialcopolymers as suspending agent in the fluid (F) injected under pressureinto a subterranean formation where said fluid (F) includes at least aportion of the solid particles (p) and/or is brought into contact withat least a portion of the solid particles (p) within the subterraneanformation subsequent to its injection.

In embodiments, a method for fracturing a subterranean formationincludes the step of injecting an aqueous fracturing fluid into at leasta portion of the subterranean formation at pressures sufficient tofracture the formation. In embodiments, the fracturing fluid includes aslurry as described herein. In embodiments, the fracturing fluidincludes a polymer of the present disclosure.

In embodiments, the polymer includes:

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; and

iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.

In embodiments, the glycol ether is selected from diethylene glycolmethyl ether, diethylene glycol ethyl ether, diethylene glycol propylether, diethylene glycol n-butyl ether, diethylene glycol t-butyl ether,diethylene glycol pentyl ether, diethylene glycol hexyl ether,diethylene glycol heptyl ether, diethylene glycol octyl ether,diethylene glycol phenyl ether, diethylene glycol methyl ether acetate,diethylene glycol ethyl ether acetate, diethylene glycol propyl etheracetate, diethylene glycol n-butyl ether acetate, diethylene glycolt-butyl ether acetate, diethylene glycol pentyl ether acetate,diethylene glycol hexyl ether acetate, diethylene glycol heptyl etheracetate, diethylene glycol octyl ether acetate, diethylene glycol phenylether acetate, dipropylene glycol methyl ether, dipropylene glycol ethylether, dipropylene glycol propyl ether, dipropylene glycol n-butylether, dipropylene glycol t-butyl ether, dipropylene glycol pentylether, dipropylene glycol hexyl ether, dipropylene glycol heptyl ether,dipropylene glycol octyl ether, dipropylene glycol phenyl ether,dipropylene glycol methyl ether acetate, dipropylene glycol ethyl etheracetate, dipropylene glycol propyl ether acetate, dipropylene glycoln-butyl ether acetate, dipropylene glycol t-butyl ether acetate,dipropylene glycol pentyl ether acetate, dipropylene glycol hexyl etheracetate, dipropylene glycol heptyl ether acetate, dipropylene glycoloctyl ether acetate and dipropylene glycol phenyl ether acetate, andcombinations thereof. In embodiments, the glycol ether is diethyleneglycol hexyl ether (DGHE).

In embodiments, prior to injecting the aqueous fracturing fluid, thepolymer is in a powder form with a particle size of from about 5 μm toabout 400 μm. In embodiments, the polymer is present in an amountranging from about 0.001 wt % to about 10 wt % based upon the totalweight of the fracturing fluid.

In embodiments, the fracturing fluid suspends the particles at atemperature from about 68° F. to about 350° F. In embodiments, thefracturing fluid suspends the particles at a temperature from about 250°F. to about 350° F. In some embodiments, the fracturing fluid suspendsthe particles at a temperature from about 300° F. to about 350° F.

In some embodiments, the fracturing fluid further includes a surfactant.In an embodiment, the surfactant is selected from, but not limited to,tridecyl alcohol ethoxylate and EO/PO block copolymers (e.g. ANTAROX31R1, ANTAROX LA EP 16, ANTAROX BL 225) In embodiments, the surfactantis present in an amount ranging from about 0.01 wt % to about 10 wt %based upon the weight of the polymer.

In embodiments, the fracturing fluid further includes a proppant. Inembodiments, the proppant is used in an amount ranging from about 20 wt% to about 60 wt % based upon the total weight of the fracturing fluid.

In some embodiments, the fracturing fluid further includes a claystabilizer. In certain embodiments, the clay stabilizer is selected fromcholine chloride, potassium chloride, ammonium chloride, sodiumchloride, calcium chloride, and combinations thereof. In otherembodiments, the clay stabilizer is present in an amount ranging fromabout 0.01 wt % to about 30 wt % based upon the total weight of thefracturing fluid.

In embodiments, the fracturing fluid further includes a frictionreducing polymer. In embodiments, the friction reducing polymer isselected from synthetic polymers, natural polymers, semi-syntheticpolymers, and mixtures thereof. Natural and semi-synthetic polymer maybe selected from xanthan gum, guar gum, modified guar gum such ascationic guar gum or hydroxypropyl guar gum, scleroglucan,schizophillan, cellulosic derivatives such as carboxymethyl cellulose,and mixtures thereof. In some embodiments, the polymer is a syntheticanionic or cationic or non-ionic or amphoteric polymer and based onnon-ionic monomers and/or cationic monomers and/or anionic monomers.

In embodiments, a method of suspending a proppant of a fracturing fluidincludes mixing an aqueous fluid and the proppant. In embodiments, theaqueous fluid includes a polymer including the polymer as describedherein.

In embodiments, the polymer includes:

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; and

iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.

In embodiments, the glycol ether is selected from diethylene glycolmethyl ether, diethylene glycol ethyl ether, diethylene glycol propylether, diethylene glycol n-butyl ether, diethylene glycol t-butyl ether,diethylene glycol pentyl ether, diethylene glycol hexyl ether,diethylene glycol heptyl ether, diethylene glycol octyl ether,diethylene glycol phenyl ether, diethylene glycol methyl ether acetate,diethylene glycol ethyl ether acetate, diethylene glycol propyl etheracetate, diethylene glycol n-butyl ether acetate, diethylene glycolt-butyl ether acetate, diethylene glycol pentyl ether acetate,diethylene glycol hexyl ether acetate, diethylene glycol heptyl etheracetate, diethylene glycol octyl ether acetate, diethylene glycol phenylether acetate, dipropylene glycol methyl ether, dipropylene glycol ethylether, dipropylene glycol propyl ether, dipropylene glycol n-butylether, dipropylene glycol t-butyl ether, dipropylene glycol pentylether, dipropylene glycol hexyl ether, dipropylene glycol heptyl ether,dipropylene glycol octyl ether, dipropylene glycol phenyl ether,dipropylene glycol methyl ether acetate, dipropylene glycol ethyl etheracetate, dipropylene glycol propyl ether acetate, dipropylene glycoln-butyl ether acetate, dipropylene glycol t-butyl ether acetate,dipropylene glycol pentyl ether acetate, dipropylene glycol hexyl etheracetate, dipropylene glycol heptyl ether acetate, dipropylene glycoloctyl ether acetate, dipropylene glycol phenyl ether acetate, andcombinations thereof. In embodiments, the glycol ether is diethyleneglycol hexyl ether (DGHE).

In embodiments, a method for fracturing a subterranean formationincludes an initial proppant-lean pad stage to initiate and propagate afracture in a subterranean formation, followed by a series ofproppant-laden stages, wherein the initial pad stage includes an aqueousfluid system comprising a polymer selected from synthetic polymers,natural polymers, semi-synthetic polymers, and mixtures thereof, and theproppant-laden stages include a composition of the present disclosure.Natural and semi-synthetic polymer may be selected from xanthan gum,guar gum, modified guar gum such as cationic guar gum or hydroxypropylguar gum, scleroglucan, schizophillan, cellulosic derivatives such ascarboxymethyl cellulose, and mixtures thereof. In embodiments, thepolymer is a synthetic anionic or cationic or non-ionic or amphotericpolymer and based on non-ionic monomers and/or cationic monomers and/oranionic monomers.

In embodiments, a method for fracturing a subterranean formationincludes the steps of combining water with a polymer in a powder form toproduce an aqueous polymer composition; pumping an initial proppant-leanaqueous fluid system comprising a friction reducing polymer into atleast a portion of the subterranean formation at a rate to incurfriction pressure losses followed by pumping a proppant-laden aqueousfluid system comprising a friction reducing polymer and the aqueouspolymer composition into at least a portion of the subterraneanformation. In embodiments, the proppant-lean aqueous fluid systemincludes a friction reducing polymer that is the same or different fromthe friction reducing polymer in the proppant-laden aqueous fluidsystem.

In embodiments, the polymer includes:

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; and

iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.In embodiments, the glycol ether includes diethylene glycol hexyl ether.

In embodiments, the method for fracturing a subterranean formationfurther includes the step of injecting a breaker into at least a portionof the subterranean formation. In an embodiment, the breaker includes anenzyme breaker. In an embodiment, the enzyme breaker is selected fromoxidoreductase, oxidase, ligase, asparaginase, and mixtures thereof.

In an embodiment, the fracturing fluid is selected from fresh water, seawater, brines, salt water, produced water, recycled water, industrialwaste water, waste water associated with oil production, andcombinations thereof.

In another embodiment, a fracturing fluid is provided, which includes apolymer in a mass concentration of from about 0.1 ppt to about 200 ppt,based upon total volume of the composition, a plurality of proppantparticles in a mass concentration of from about 0.1 lb/gal to about 12lb/gal, based upon total volume of the composition, and a breakerpresent in a mass concentration of from 0 ppt to about 20 ppt based upontotal volume of the composition.

Also provided is a method of acidizing a formation penetrated by awellbore that includes the steps of injecting into the wellbore at apressure below formation fracturing pressure a treatment fluid thatincludes a polymer according to the present disclosure and an aqueousacid and allowing the treatment fluid to acidize the formation and/orself-divert into the formation. As used herein, the term, “self-divert”refers to a composition that viscosifies as it stimulates the formationand, in so doing, diverts any remaining acid into zones of lowerpermeability in the formation.

In embodiments, a method of acidizing a subterranean formationpenetrated by a wellbore includes the steps of: (a) injecting into thewellbore at a pressure below subterranean formation fracturing pressurea treatment fluid having a first viscosity and including an aqueous acidand a polymer; (b) forming at least one void in the subterraneanformation with the treatment fluid; and (c) allowing the treatment fluidto attain a second viscosity that is greater than the first viscosity.

In embodiments, the polymer includes:

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; and

iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.In embodiments, the glycol ether includes diethylene glycol hexyl ether.

In other embodiments, the method further includes forming at least onevoid in the subterranean formation with the treatment fluid after thefluid has attained the second viscosity.

In another embodiment, the method further includes reducing theviscosity of the treatment fluid to a viscosity that is less than thesecond viscosity.

The treatment fluid may further include one or more additives. In someembodiments, the fluid includes one or more additives selected fromcorrosion inhibitors, iron control agents, clay stabilizers, calciumsulfate inhibitors, scale inhibitors, mutual solvents, non-emulsifiers,anti-slug agents, and combinations thereof. In certain embodiments, thecorrosion inhibitor is selected from alcohols (e.g. acetylenics);cationics (e.g. quaternary ammonium salts, imidazolines, and alkylpyridines); and nonionics (e.g. alcohol ethoxylates).

Suitable aqueous acids include those compatible with the polymers of thepresent disclosure for use in an acidizing process. In embodiments, theaqueous acid is selected from hydrochloric acid, hydrofluoric acid,formic acid, acetic acid, sulfamic acid, and combinations thereof. Inembodiments, the treatment fluid includes acid in an amount up to 30 wt% by total weight of the fluid.

In embodiments, the treatment fluid further includes one or moreadditives. In an embodiment, the fluid includes one or more additivesselected from corrosion inhibitors, iron control agents, claystabilizers, calcium sulfate inhibitors, scale inhibitors, mutualsolvents, non-emulsifiers, anti-slug agents, biocides, paraffininhibitors, tracers and combinations thereof. In an embodiment, thecorrosion inhibitor is selected from alcohols (e.g. acetylenics);cationics (e.g. quaternary ammonium salts, imidazolines, and alkylpyridines); and nonionics (e.g. alcohol ethoxylates). In someembodiments, the additive is a dry additive. In other embodiments, oneor more dry additives are blended with a composition of the presentdisclosure.

In embodiments, compositions of the present disclosure are combined witha brine to viscosify the fluid. In an embodiment, the brine is asolids-free high density (e.g. a density in the range of about 8.5 toabout 21 pounds per gallon (about 1020 up to about 2500 kg/m3))(“heavy”) brine composition suitable for applications in drilling,completion and the stimulation of subterranean oil and gas wells. Fluidsused in drilling, completion and stimulation of the subterranean oil andgas wells include, but are not necessarily limited to, completionfluids, perforating fluids, water-based drilling fluids, invertedemulsion drilling fluid, gravel pack, drill-in fluids, packer fluids,workover fluids, displacement, fracking fluids and remediation fluids.

Compositions of the present disclosure can also be used to limit orprevent pump damage during surface transport of proppant. In surfacetransport, proppant (e.g. sand) can settle causing damage in the pump.Maintaining sand influx is necessary to produce oil at economic rates.If a mechanical failure or a wellbore or pump blockage by sand occurs, aworkover is required. Tubular goods are withdrawn, and beforereinstallation, the well is thoroughly cleaned of sand using amechanical bailer, a pump-to-surface truck, a jet pump, foam treatment,or other techniques. Oil production is reinitiated after pumpreinstallation.

In embodiments, a method for suspending and transporting proppant on thesurface (e.g. above ground) includes a step of mixing an aqueous fluidand proppant and transporting the combination through at least one pump.In embodiments, the fluid includes the polymer as described herein.

In embodiments, the polymer includes:

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; and

iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.In embodiments, the glycol ether includes diethylene glycol hexyl ether.

Compositions of the present disclosure can also be used in drillingfluids or muds. A drilling fluid or mud is a specially designed fluidthat is circulated through a drill bit within a wellbore as the wellboreis being drilled. The drilling fluid is circulated back to the surfaceof the wellbore with drill cuttings for removal therefrom. The drillingfluid maintains a specific, balanced hydrostatic pressure within thewellbore, permitting all or most of the drilling fluid to be circulatedback to the surface. Additionally, among other things, the drillingfluid facilitates cooling and lubricating the drill bit, aiding insupport of the drill pipe and drill bit, and providing a hydrostatichead to maintain the integrity of the wellbore walls and prevent wellblowouts. In an embodiment, a method of drilling a wellbore is providedthat includes the step of pumping a composition of the presentdisclosure into a wellbore.

Compositions of the present disclosure can also be used in gravelpacking methods. Some oil and gas wells are completed in unconsolidatedformations that contain loose fines and sand. When fluids are producedfrom these wells, the loose fines and sand can migrate with the producedfluids and can damage equipment, such electric submersible pumps (ESP)and other systems. For this reason, completions for these wells canrequire sand screens for sand control. For hydrocarbon wells, esp.horizontal wells, the completion has screen sections with a perforatedinner tube and an overlying screen portion. The purpose of the screen isto block the flow of particulate matter into the interior of theproduction tubing.

A gravel pack operation is one way to reduce the inflow of particulatematter before it reaches the sand screen. In the gravel pack operation,gravel (e.g., sand) is packed in the borehole annulus around the sandscreen. The gravel is a specially sized particulate material, such asgraded sand or proppant. When packed around the sand screen in theborehole annulus, the packed gravel acts as a filter to keep any finesand sand of the formation from migrating with produced fluids to thesand screen. The packed gravel also provides the producing formationwith a stabilizing force that can prevent the borehole annulus fromcollapsing. In general, gravel packing is used to stabilize theformation and maintain well productivity. Gravel packing is applied inconjunction with hydraulic fracturing, but at much lower pressures.

Compositions of the present disclosure can also be used in circulatingfluids in drill-out operations and/or to remove debris from a wellbore.The wellbore to which the circulating fluid is introduced penetrates asubterranean reservoir. In drill-out, a barrier in the wellbore is firstmilled leaving behind debris, such as rubber and metal. Debris in thewellbore might alternatively include sand, residual fluids, nylon,carbon composites, etc. The area is cleaned by circulating water orbrine and a composition of the present disclosure into the zone.

Drill-out is typically performed by a coiled tubing unit (having apositive displacement motor and a mill/bit run) or a jointed pipe. Withhorizontal wells, coiled tubing is more typically used. Duringdrill-out, circulating fluid is introduced into the wellbore at the endof the tubing or pipe and returns up into the annulus. In embodiments, adrill-out method includes the steps of combining water with a polymer ina powder form to produce an aqueous polymer composition; milling abarrier in a wellbore, circulating a fluid comprising the aqueouspolymer composition through the wellbore, and removing debris from thewellbore in the circulating fluid. In embodiments, a wellbore is sweptof debris by circulating a fluid comprising a composition of the presentdisclosure through the wellbore, and removing debris from the wellborein the circulating fluid.

In embodiments, the polymer includes:

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; and

iii) at least one glycol ether having a structure of

q wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q arethe same or different and p and q are independently an integer from 1 to6. In embodiments, the glycol ether includes diethylene glycol hexylether.

Compositions of the present disclosure can be used in various stages ofwellbore cementing operations. Preparation of the wellbore for cementingoperations may be important in achieving optimal zonal isolation.Conventionally, wellbores may be cleaned and prepared for the cementcomposition with a fluid train that precedes the cement composition andcan include spacer fluids, flushes, water-based muds, and the like.Spacer fluids may be used in wellbore preparation for drilling fluiddisplacement before introduction of the cement composition. The spacerfluids may enhance solids removal while also separating the drillingfluid from a physically incompatible fluid, such as a cementcomposition. Spacer fluids may also be placed between different drillingfluids during drilling change outs or between a drilling fluid andcompletion brine. In embodiments, a spacer fluid including a compositionof the present disclosure is provided. In embodiments, a system isprovided, which includes a polymer as described herein; a base fluid foruse in the spacer fluid; and a pump fluid fluidly coupled to a tubularin fluid communication with a wellbore, wherein the tubular isconfigured to convey the spacer fluid to the wellbore. In yet anotherembodiment, a system is provided, which includes a spacer fluid thatincludes water and the polymer as described herein; and a pump fluidfluidly coupled to a tubular in fluid communication with a wellbore. Inembodiments, the tubular is configured to convey the spacer fluid to thewellbore.

In embodiments, compositions of the present disclosure are used in flushfluids. In an embodiment a method is provided that includes the step ofintroducing a flush fluid into a well bore penetrating at least aportion of a subterranean formation, wherein the flush fluid includes acomposition of the present disclosure. Flushes are used to thin anddisperse drilling-fluid particles and are used to separate drillingfluids and cementing slurries. Flushes can be used with eitherwater-based or oil-based drilling fluids. In embodiments, flushesprepare both the pipe and formation for the cementing operation.

Compositions of the present disclosure can also be used as cement (e.g.hydraulic cement) suspending agents. After the drilling of a wellbore isterminated, a string of pipe, e.g., casing, is run in the wellbore.Primary cementing is then usually performed whereby a cementing fluid,usually including water, cement, and particulate additives, is pumpeddown through the string of pipe and into the annulus between the stringof pipe and the walls of the wellbore to allow the cementing fluid toset into an impermeable cement column and thereby seal the annulus.Subsequent secondary cementing operations, i.e., any cementing operationafter the primary cementing operation, may also be performed. Oneexample of a secondary cementing operation is squeeze cementing wherebya cementing fluid is forced under pressure to areas of lost integrity inthe annulus to seal off those areas.

A common problem in petroleum well cementing is the loss of filtratefrom the cement slurry into porous low pressure zones in the earthformation surrounding the well annulus. This fluid loss is undesirablesince it can result in dehydration of the cement slurry, and it causesthick filter cakes of cement solids which can plug the well bore;moreover the fluid lost can damage sensitive formations. The presentdisclosure provides a method that includes the steps of: slurrying acement composition with water, admixing a composition of the presentdisclosure therewith to make a cement slurry exhibiting reduced fluidloss, and cementing a casing string in a wellbore by placing the cementslurry between the casing string and an exposed borehole wall.

Settling of solids in a cement slurry is also a possibility under avariety conditions. For example, when cement is placed in a wellboredrilled at a high angle from the vertical, settling can occur. Settlingis also possible when high water content slurries are used. Undesirableconsequences of the solids settling include free water and a densitygradient in the set cement. To inhibit settling, cement suspendingagents can be added to the cementing fluid. In embodiments, provided amethod that includes the steps of: combining water with a polymer in apowder form to produce an aqueous polymer composition; providing acementing fluid that includes an aqueous liquid, a hydraulic cement, anda cement suspending agent that includes the aqueous polymer composition;placing the cementing fluid in a wellbore penetrating a subterraneanformation; and allowing the cementing fluid to set therein.

In embodiments, the polymer includes:

i) at least one hydrophobic monomer selected from n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof;

ii) at least one hydrophilic monomer selected from acrylate, acrylatesalts, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; and

iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.In embodiments, the glycol ether includes diethylene glycol hexyl ether.

During well construction, well production and well abandonment it may benecessary to perform operations which require minimizing or terminatingfluid flow between wellbore and formation. In the majority of cases,such operations are performed to restore, prolong or enhance theproduction of hydrocarbons. To maintain well control, workoveroperations require that the well be filled with fluid with hydrostaticpressure in excess of the reservoir pressure. It is commonly referred aswell “kill” operation. Well kills may be achieved by a variety of means,including the introduction of drilling or completion fluids that exertsufficient hydrostatic pressure in the wellbore to prevent formationfluid production. The fluid is often maintained in the wellbore for theentire duration of the workover operation.

Compositions of the present disclosure are suitable for use in well killoperations. In embodiments, a method for treating a subterranean wellhaving a borehole is provided, which includes the steps of: combiningwater with a polymer in a powder form to produce an aqueous polymercomposition; placing a treatment fluid that includes the aqueous polymercomposition in the borehole such that the treatment fluid contacts aliner, a downhole filter, perforations, natural or induced fractures orsubterranean formation or combinations thereof; and allowing thetreatment fluid to flow into the liner, downhole filter, perforation,natural or induced fracture or subterranean formation, wherein furtherfluid movement between wellbore and subterranean formation is preventedor reduced after flow of the treatment fluid. In an embodiment, thetreatment fluid further includes a heavy brine and/or particles.

While specific embodiments are discussed, the specification isillustrative only and not restrictive. Many variations of thisdisclosure will become apparent to those skilled in the art upon reviewof this specification.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as is commonly understood by one of skill in theart to which this specification pertains.

As used in the specification and claims, the singular form “a”, “an” and“the” includes plural references unless the context clearly dictatesotherwise.

As used herein, and unless otherwise indicated, the term “about” or“approximately” means an acceptable error for a particular value asdetermined by one of ordinary skill in the art, which depends in part onhow the value is measured or determined. In certain embodiments, theterm “about” or “approximately” means within 1, 2, 3, or 4 standarddeviations. In certain embodiments, the term “about” or “approximately”means within 50%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%,0.5%, or 0.05% of a given value or range.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between andincluding the recited minimum value of 1 and the recited maximum valueof 10; that is, having a minimum value equal to or greater than 1 and amaximum value of equal to or less than 10. Because the disclosednumerical ranges are continuous, they include every value between theminimum and maximum values. Unless expressly indicated otherwise, thevarious numerical ranges specified in this application areapproximations.

The present disclosure will further be described by reference to thefollowing examples. The following examples are merely illustrative andare not intended to be limiting.

EXAMPLE Chemicals and Materials

-   -   SDS: sodium dodecyl sulfate (manufactured by Fengyi, China)    -   DI water: distilled water    -   MEHQ: 4-methoxyphenol or mequinol    -   LMA: lauryl methacrylate    -   RHODIXAN RAl: O-ethyl-S-(1-methoxycarbonyl)ethyl dithiocarbonate        (manufactured by Solvay)    -   HEXYL CARBITOL™: diethylene glycol hexyl ether (manufactured by        Dow, USA)    -   SNF AM: Acrylamide (manufactured by SNF)    -   NaAMPS: 2-acrylamido-2-methylpropane sulfonic acid sodium salt    -   Anti-foam agent: BYK-LP022748 (manufactured by BYK, Japan)    -   Na₄EDTA: ethylenediaminetetraacetic acid tetrasodium salt        (VERSENE 100 manufactured by DOW, USA)    -   NaPS: sodium peroxosulphate or sodium persulfate    -   NaFS: sodium formaldehyde sulfoxylate    -   IRIS: diester solvent named RHODIASOLV® IRIS (manufacture by        Solvay, Belgium)    -   RHODASURF® 91-6: an ethoxylated alcohol with 6 mole of EO        (manufacture by Solvay, Belgium)

Example 1: Methods of Preparation for PPS Containing In SituIncorporated Diethylene Glycol Hexyl Ether (DGHE)

The lab formulation of the PPS synthesis is shown below. The solventDGHE was firstly included in the micellar phase. After the aqueous phasewas prepared, the micellar phase containing the DGHE was mixed togetherwith the aqueous phase. Following the nitrogen purge, the reaction wasinitiated by the initiators system shown below. After the synthesis, theresulting PPS gel was processed in the fluid bed dryer, grinded andsieved to obtain final PPS powder product.

TABLE 1 Initiators: (Target initiation temp Micellar phase: Aqueousphase: 25-30° C.) 103.2 g of SDS 429.7 g of DI water 3 g of V-50 (10% inDI (China Fengyi, 31%) 326.2 g of SNF AM (50%) water) 37 g of DI water262.9 g of NaAMPS 2403 0.4 g of NaPS (3% in DI 0.021 g MEHQ (50%) water)(10 ppm NaPS) 5.45 g of LMA 0.12 g of Anti-foam BYK- 0.75 gof NaFS (5%in 0.029 g of LP022748 DI water) RHODIXAN RA1 0.12 g of Na₄EDTA 30.0 gof HEXYL (versene 100, 0.3 g) CARBITOL ™ Adjust pH to 6 using 10% H2SO4

Testing Protocols of PPS

1. To a waring blender (500 ml size), add 200 g 1K TDS water and thenadd 0.3 wt % (0.6 g) of PPS powder to the water while is it is beingstirred at 2000 rpm, stir the mixture for 3 min. Check and recordviscosity using Fann 35 at 300 rpm.

2. Add 25 wt % of 20/40 mesh sand and mix well, observe sand suspensionproperties at both room temperature and 180° F.

3. The acceptable PPS should suspend the sand for at least 3 hours atboth room temperature and 180° F.

Example 2: PPS Samples with and without Diethylene Glycol Hexyl Ether(DGHE)

The table below showed PPS samples containing in situ incorporatedadditives during synthesis. The following samples shown in the tablewere all hydrated for 3 min in a waring blender at 2,500 rpm beforeviscosity measurement and sand suspension testing.

TABLE 2 Additive Additive #2 #3 (2 wt % (2 wt % of Urea; and Urea; and12.5 wt % 12.5 wt % 0.3% Additive#1 of IRIS; of IRIS; Powder in (2 wt %of and and Additive#4 1K TDS + Urea; and 0.5 wt % of 0.75 wft % (1 wt %of Additive#5 1 gpt No 12.5 wt % Rhodasurf Rhodasurf Rhodasurf (10 wt %Claymax additive Iris) 91-6) 91-6) 91-6) of DGHE) Viscosity 4.5 24.126.7 22.3 8.6 45.5 (cp) at 511 S⁻¹ Sand No No No No No YES Suspension

Among these samples, the only sample that can fully hydrate and suspendsand is the sample with 10% DGHE at low shear rate of 2,500 rpm. Thissuggests the fast hydration of the PPS powder when the DGHE wasincorporated in the system. In addition, the field application requiresthe polymers to hydrate fast at low shear rate for a short period oftime such as 3 min and the PPS sample containing DGHE meets allrequirements.

Example 3: Comparison of 10% DGHE In Situ Incorporated Vs Post Added tothe Hydration Water

TABLE 3 0.3% Powder in PPS sample with 10 wt % PPS sample with 10 wt %1K TDS + DGHE in situ incorporated DGHE post added to 1 gpt Claymaxduring synthesis hydration water Viscosity (cp) 45.5 10.5 at 511S⁻¹ SandSuspension YES No

The two samples above clearly showed the advantages of in situincorporation of DGHE versus post addition to the hydration water.

The disclosed subject matter has been described with reference tospecific details of particular embodiments thereof. It is not intendedthat such details be regarded as limitations upon the scope of thedisclosed subject matter except insofar as and to the extent that theyare included in the accompanying claims.

Therefore, the exemplary embodiments described herein are well adaptedto attain the ends and advantages mentioned as well as those that areinherent therein. The particular embodiments disclosed above areillustrative only, as the exemplary embodiments described herein may bemodified and practiced in different but equivalent manners apparent tothose skilled in the art having the benefit of the teachings herein.Furthermore, no limitations are intended to the details of constructionor design herein shown, other than as described in the claims below. Itis therefore evident that the particular illustrative embodimentsdisclosed above may be altered, combined, or modified and all suchvariations are considered within the scope and spirit of the exemplaryembodiments described herein. The exemplary embodiments described hereinillustratively disclosed herein suitably may be practiced in the absenceof any element that is not specifically disclosed herein and/or anyoptional element disclosed herein. While compositions and methods aredescribed in terms of “comprising,” “containing,” or “including” variouscomponents or steps, the compositions and methods can also “consistessentially of” or “consist of” the various components, substances andsteps. As used herein the term “consisting essentially of” shall beconstrued to mean including the listed components, substances or stepsand such additional components, substances or steps which do notmaterially affect the basic and novel properties of the composition ormethod. In some embodiments, a composition in accordance withembodiments of the present disclosure that “consists essentially of” therecited components or substances does not include any additionalcomponents or substances that alter the basic and novel properties ofthe composition. If there is any conflict in the usages of a word orterm in this specification and one or more patent or other documentsthat may be incorporated herein by reference, the definitions that areconsistent with this specification should be adopted.

What is claimed:
 1. A composition comprising: i) at least onehydrophobic monomer selected from the group consisting of n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof; ii) at least one hydrophilicmonomer selected from the group consisting of acrylate, acrylate salts,acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is C₁-C₈ alkyl or phenyl; p and qare the same or different and p and q are independently an integer from1 to 6, wherein the composition has a hydration rate of about 70% orgreater.
 2. The composition of claim 1, wherein p and q areindependently 2 or
 3. 3. The composition of claim 1, wherein the glycolether comprises one or more selected from the group consisting ofdiethylene glycol methyl ether, diethylene glycol ethyl ether,diethylene glycol propyl ether, diethylene glycol n-butyl ether,diethylene glycol t-butyl ether, diethylene glycol pentyl ether,diethylene glycol hexyl ether, diethylene glycol heptyl ether,diethylene glycol octyl ether, diethylene glycol phenyl ether,diethylene glycol methyl ether acetate, diethylene glycol ethyl etheracetate, diethylene glycol propyl ether acetate, diethylene glycoln-butyl ether acetate, diethylene glycol t-butyl ether acetate,diethylene glycol pentyl ether acetate, diethylene glycol hexyl etheracetate, diethylene glycol heptyl ether acetate, diethylene glycol octylether acetate, diethylene glycol phenyl ether acetate, dipropyleneglycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycolpropyl ether, dipropylene glycol n-butyl ether, dipropylene glycolt-butyl ether, dipropylene glycol pentyl ether, dipropylene glycol hexylether, dipropylene glycol heptyl ether, dipropylene glycol octyl ether,dipropylene glycol phenyl ether, dipropylene glycol methyl etheracetate, dipropylene glycol ethyl ether acetate, dipropylene glycolpropyl ether acetate, dipropylene glycol n-butyl ether acetate,dipropylene glycol t-butyl ether acetate, dipropylene glycol pentylether acetate, dipropylene glycol hexyl ether acetate, dipropyleneglycol heptyl ether acetate, dipropylene glycol octyl ether acetate, anddipropylene glycol phenyl ether acetate.
 4. The composition of claim 1,wherein the at least one glycol ether is diethylene glycol hexyl ether.5. The composition of claim 1, wherein the composition comprises the atleast one glycol ether in an amount from about 3 wt % to about 15 wt %based on the total weight of the composition.
 6. The composition ofclaim 1, further comprising a salt containing alkyl sulfate (—SO₄)anion.
 7. The composition of claim 6, wherein the salt comprises sodiumlauryl sulfate.
 8. A method of producing a polymer powder, comprising:combining a composition of claim 1 and water to form an aqueous polymercomposition; synthesizing a polymer by polymerizing the aqueous polymercomposition; drying the polymer; and forming the polymer powder from thedried polymer.
 9. The method of claim 8, wherein the polymer powder isformed by grinding or milling.
 10. The method of claim 8, wherein thepolymer powder has a particle size of from about 1 μm to about 1 mm. 11.A powder composition comprising a polymer comprising: i) at least onehydrophobic monomer selected from the group consisting of n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof; ii) at least one hydrophilicmonomer selected from the group consisting of acrylate, acrylate salts,acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6.12. The powder composition of claim 11, wherein the glycol ether isdiethylene glycol hexyl ether.
 13. The powder composition of claim 11,wherein the powder composition has a particle size of from about 1 μm toabout 1 mm.
 14. A slurry comprising: a polymer comprising: i) at leastone hydrophobic monomer selected from the group consisting of n-hexyl(meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl(meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate,myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl(meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl(meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl(meth)acrylamide, and combinations thereof; ii) at least one hydrophilicmonomer selected from the group consisting of acrylate, acrylate salts,acrylamide, 2-acrylamido-2-methylpropane sulfonic acid,2-acrylamido-2-methylpropane sulfonic acid salts, and combinationsthereof; iii) at least one glycol ether having a structure of

wherein R¹ is hydrogen or acetate; R² is alkyl or aryl; p and q are thesame or different and p and q are independently an integer from 1 to 6;an aqueous component; and a proppant, wherein the polymer in the slurryhas a hydration rate of about 70% or greater.
 15. The slurry of claim14, wherein the aqueous component is selected from the group consistingof distilled water, fresh water, sea water, brines, salt water, producedwater, recycled water, industrial waste water, waste water associatedwith oil production, and combinations thereof.
 16. The slurry of claim14, wherein the glycol ether is diethylene glycol hexyl ether.
 17. Amethod of fracturing a subterranean formation comprising injecting afracturing fluid comprising a slurry of claim 14 into at least a portionof the subterranean formation at pressures sufficient to fracture theformation.
 18. The method of claim 17, wherein the slurry comprisesdiethylene glycol hexyl ether.
 19. A method of suspending a proppant ofa fracturing fluid comprising: mixing an aqueous fluid and the proppant,wherein the aqueous fluid comprises a polymer comprising a compositionof claim 1 and water.
 20. The method of claim 19, wherein the polymercomprises diethylene glycol hexyl ether.